1
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Zhang W, Poon TF, Tsang CW, Wang W, Liu X, Xie J, Lam ST, Wang S, Lai KT, Pourret A, Seyfarth G, Knebel G, Yu WC, Goh SK. Large Fermi surface in pristine kagome metal CsV 3Sb 5 and enhanced quasiparticle effective masses. Proc Natl Acad Sci U S A 2024; 121:e2322270121. [PMID: 38753515 DOI: 10.1073/pnas.2322270121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/17/2024] [Indexed: 05/18/2024] Open
Abstract
The kagome metal CsV[Formula: see text]Sb[Formula: see text] is an ideal platform to study the interplay between topology and electron correlation. To understand the fermiology of CsV[Formula: see text]Sb[Formula: see text], intensive quantum oscillation (QO) studies at ambient pressure have been conducted. However, due to the Fermi surface reconstruction by the complicated charge density wave (CDW) order, the QO spectrum is exceedingly complex, hindering a complete understanding of the fermiology. Here, we directly map the Fermi surface of the pristine CsV[Formula: see text]Sb[Formula: see text] by measuring Shubnikov-de Haas QOs up to 29 T under pressure, where the CDW order is completely suppressed. The QO spectrum of the pristine CsV[Formula: see text]Sb[Formula: see text] is significantly simpler than the one in the CDW phase, and the detected oscillation frequencies agree well with our density functional theory calculations. In particular, a frequency as large as 8,200 T is detected. Pressure-dependent QO studies further reveal a weak but noticeable enhancement of the quasiparticle effective masses on approaching the critical pressure where the CDW order disappears, hinting at the presence of quantum fluctuations. Our high-pressure QO results reveal the large, unreconstructed Fermi surface of CsV[Formula: see text]Sb[Formula: see text], paving the way to understanding the parent state of this intriguing metal in which the electrons can be organized into different ordered states.
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Affiliation(s)
- Wei Zhang
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Tsz Fung Poon
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Chun Wai Tsang
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Wenyan Wang
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - X Liu
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - J Xie
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - S T Lam
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Shanmin Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518005, China
| | - Kwing To Lai
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - A Pourret
- Université Grenoble Alpes, Commissariat à l'énergie atomique et aux énergies alternatives, Institut polytechnique de Grenoble, Institut de recherche interdisciplinaire de Grenoble, Laboratoire Photonique Electronique et Ingénierie Quantiques, Grenoble 38000, France
| | - G Seyfarth
- Laboratoire National des Champs Magnétiques Intenses, Université Grenoble Alpes, Grenoble 38000, France
- Laboratoire National des Champs Magnétiques Intenses, Centre National de la Recherche Scientifique, Université Paul Sabatier Toulouse 3, Institut National des Sciences Appliquées Toulouse, European Magnetic Field Laboratory, Grenoble 38000, France
| | - G Knebel
- Université Grenoble Alpes, Commissariat à l'énergie atomique et aux énergies alternatives, Institut polytechnique de Grenoble, Institut de recherche interdisciplinaire de Grenoble, Laboratoire Photonique Electronique et Ingénierie Quantiques, Grenoble 38000, France
| | - Wing Chi Yu
- Department of Physics, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Swee K Goh
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
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2
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Yan L, Bu K, Li Z, Zhang Z, Xia W, Li M, Li N, Guan J, Liu X, Ning J, Zhang D, Guo Y, Wang X, Yang W. Double Superconducting Dome of Quasi Two-Dimensional TaS 2 in Non-Centrosymmetric van der Waals Heterostructure. Nano Lett 2024. [PMID: 38739273 DOI: 10.1021/acs.nanolett.4c00579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
Two-dimensional van der Waals heterostructures (2D-vdWHs) based on transition metal dichalcogenides (TMDs) provide unparalleled control over electronic properties. However, the interlayer coupling is challenged by the interfacial misalignment and defects, which hinders a comprehensive understanding of the intertwined electronic orders, especially superconductivity and charge density wave (CDW). Here, by using pressure to regulate the interlayer coupling of non-centrosymmetric 6R-TaS2 vdWHs, we observe an unprecedented phase diagram in TMDs. This phase diagram encompasses successive suppression of the original CDW states from alternating H-layer and T-layer configurations, the emergence and disappearance of a new CDW-like state, and a double superconducting dome induced by different interlayer coupling effects. These results not only illuminate the crucial role of interlayer coupling in shaping the complex phase diagram of TMD systems but also pave a new avenue for the creation of a novel family of bulk heterostructures with customized 2D properties.
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Affiliation(s)
- Limin Yan
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
- School of Science, Inner Mongolia University of Science and Technology, Baotou 014010, People's Republic of China
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Kejun Bu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Zhongyang Li
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Zihan Zhang
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Mingtao Li
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Nana Li
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Jiayi Guan
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
- School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xuqiang Liu
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Jiahao Ning
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
| | - Dongzhou Zhang
- GSECARS, University of Chicago, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai 201210, People's Republic of China
| | - Xin Wang
- State Key Laboratory of Superhard Materials, Department of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wenge Yang
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China
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3
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Frachet M, Wang L, Xia W, Guo Y, He M, Maraytta N, Heid R, Haghighirad AA, Merz M, Meingast C, Hardy F. Colossal c-Axis Response and Lack of Rotational Symmetry Breaking within the Kagome Planes of the CsV_{3}Sb_{5} Superconductor. Phys Rev Lett 2024; 132:186001. [PMID: 38759199 DOI: 10.1103/physrevlett.132.186001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 03/14/2024] [Accepted: 03/26/2024] [Indexed: 05/19/2024]
Abstract
The kagome materials AV_{3}Sb_{5} (A=K, Rb, Cs) host an intriguing interplay between unconventional superconductivity and charge-density waves. Here, we investigate CsV_{3}Sb_{5} by combining high-resolution thermal-expansion, heat-capacity, and electrical resistance under strain measurements. We directly unveil that the superconducting and charge-ordered states strongly compete, and that this competition is dramatically influenced by tuning the crystallographic c axis. In addition, we report the absence of additional bulk phase transitions within the charge-ordered state, notably associated with rotational symmetry breaking within the kagome planes. This suggests that any breaking of the C_{6} invariance occurs via different stacking of C_{6}-symmetric kagome patterns. Finally, we find that the charge-density-wave phase exhibits an enhanced A_{1g}-symmetric elastoresistance coefficient, whose large increase at low temperature is driven by electronic degrees of freedom.
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Affiliation(s)
- Mehdi Frachet
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
| | - Liran Wang
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 201210, China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 201210, China
| | - Mingquan He
- Low Temperature Physics Laboratory, College of Physics and Center of Quantum Materials and Devices, Chongqing University, Chongqing 401331, China
| | - Nour Maraytta
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
| | - Rolf Heid
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
| | - Amir-Abbas Haghighirad
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
| | - Michael Merz
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
- Karlsruhe Nano Micro Facility (KNMFi), Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Christoph Meingast
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
| | - Frédéric Hardy
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
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4
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Wu L, Si J, Guan S, Zhang H, Dou J, Luo J, Yang J, Yu H, Zhang J, Ma X, Yang P, Zhou R, Liu M, Hong F, Yu X. Record-High T_{c} and Dome-Shaped Superconductivity in a Medium-Entropy Alloy TaNbHfZr under Pressure up to 160 GPa. Phys Rev Lett 2024; 132:166002. [PMID: 38701470 DOI: 10.1103/physrevlett.132.166002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/06/2024] [Accepted: 03/25/2024] [Indexed: 05/05/2024]
Abstract
Superconductivity has been one of the focal points in medium and high-entropy alloys (MEAs-HEAs) since the discovery of the body-centered cubic (bcc) HEA superconductor in 2014. Until now, the superconducting transition temperature (T_{c}) of most MEA and HEA superconductors has not exceeded 10 K. Here, we report a TaNbHfZr bulk MEA superconductor crystallized in the BCC structure with a T_{c} of 15.3 K which set a new record. During compression, T_{c} follows a dome-shaped curve. It reaches a broad maximum of roughly 15 K at around 70 GPa before decreasing to 9.3 K at 157.2 GPa. First-principles calculations attribute the dome-shaped curve to two competing effects, that is, the enhancement of the logarithmically averaged characteristic phonon frequency ω_{log} and the simultaneous suppression of the electron-phonon coupling constant λ. Thus, TaNbHfZr MEA may have a promising future for studying the underlying quantum physics, as well as developing new applications under extreme conditions.
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Affiliation(s)
- Liyunxiao Wu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jianguo Si
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Shixue Guan
- School of Applied Science, Beijing Information Science and Technology University, Beijing 100192, China
| | - He Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jie Dou
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Luo
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jie Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hui Yu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jiawei Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoli Ma
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Pengtao Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Rui Zhou
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Miao Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fang Hong
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Xiaohui Yu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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5
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Huang Z, Han X, Zhao Z, Liu J, Li P, Tan H, Wang Z, Yao Y, Yang H, Yan B, Jiang K, Hu J, Wang Z, Chen H, Gao HJ. Tunable vortex bound states in multiband CsV 3Sb 5-derived kagome superconductors. Sci Bull (Beijing) 2024; 69:885-892. [PMID: 38383234 DOI: 10.1016/j.scib.2024.01.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/27/2023] [Accepted: 01/23/2024] [Indexed: 02/23/2024]
Abstract
Vortices and bound states offer an effective means of comprehending the electronic properties of superconductors. Recently, surface-dependent vortex core states have been observed in the newly discovered kagome superconductors CsV3Sb5. Although the spatial distribution of the sharp zero energy conductance peak appears similar to Majorana bound states arising from the superconducting Dirac surface states, its origin remains elusive. In this study, we present observations of tunable vortex bound states (VBSs) in two chemically-doped kagome superconductors Cs(V1-xTrx)3Sb5 (Tr = Ta or Ti), using low-temperature scanning tunneling microscopy/spectroscopy. The CsV3Sb5-derived kagome superconductors exhibit full-gap-pairing superconductivity accompanied by the absence of long-range charge orders, in contrast to pristine CsV3Sb5. Zero-energy conductance maps demonstrate a field-driven continuous reorientation transition of the vortex lattice, suggesting multiband superconductivity. The Ta-doped CsV3Sb5 displays the conventional cross-shaped spatial evolution of Caroli-de Gennes-Matricon bound states, while the Ti-doped CsV3Sb5 exhibits a sharp, non-split zero-bias conductance peak (ZBCP) that persists over a long distance across the vortex. The spatial evolution of the non-split ZBCP is robust against surface effects and external magnetic field but is related to the doping concentrations. Our study reveals the tunable VBSs in multiband chemically-doped CsV3Sb5 system and offers fresh insights into previously reported Y-shaped ZBCP in a non-quantum-limit condition at the surface of kagome superconductor.
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Affiliation(s)
- Zihao Huang
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Xianghe Han
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Zhen Zhao
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jinjin Liu
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China; Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, China
| | - Pengfei Li
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hengxin Tan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Zhiwei Wang
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China; Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, China
| | - Yugui Yao
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China; Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, China
| | - Haitao Yang
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China; Hefei National Laboratory, Hefei 230088, China
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Kun Jiang
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiangping Hu
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill MA 02467, USA
| | - Hui Chen
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China; Hefei National Laboratory, Hefei 230088, China.
| | - Hong-Jun Gao
- Beijing National Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China; Hefei National Laboratory, Hefei 230088, China.
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6
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Li H, Kim YB, Kee HY. Intertwined Van Hove Singularities as a Mechanism for Loop Current Order in Kagome Metals. Phys Rev Lett 2024; 132:146501. [PMID: 38640369 DOI: 10.1103/physrevlett.132.146501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/28/2023] [Accepted: 02/27/2024] [Indexed: 04/21/2024]
Abstract
Recent experiments on kagome metals AV_{3}Sb_{5} (A=Cs,Rb,K) indicated spontaneous time-reversal symmetry breaking in the charge density wave state in the absence of static magnetization. The loop current order (LCO) is proposed as its cause, but a microscopic model explaining the emergence of LCO through electronic correlations has not been firmly established. We show that the coupling between van Hove singularities with distinct mirror symmetries is a key ingredient to generate LCO ground state. By constructing an effective model, we find that when multiple van Hove singularities with opposite mirror eigenvalues are close in energy, the nearest-neighbor electron repulsion favors a ground state with coexisting LCO and charge bond order. It is then demonstrated that this mechanism applies to the kagome metals AV_{3}Sb_{5}. Our findings provide an intriguing mechanism of LCO and pave the way for a deeper understanding of complex quantum phenomena in kagome systems.
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Affiliation(s)
- Heqiu Li
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - Yong Baek Kim
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- School of Physics, Korea Institute for Advanced Study, Seoul 02455, Korea
| | - Hae-Young Kee
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Canadian Institute for Advanced Research, CIFAR Program in Quantum Materials, Toronto, Ontario M5G 1M1, Canada
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7
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Zhang B, Tan H, Yan B, Xu C, Xiang H. Atomistic Origin of Diverse Charge Density Wave States in CsV_{3}Sb_{5}. Phys Rev Lett 2024; 132:096101. [PMID: 38489621 DOI: 10.1103/physrevlett.132.096101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 10/22/2023] [Accepted: 02/05/2024] [Indexed: 03/17/2024]
Abstract
Kagome metals AV_{3}Sb_{5} (A=K, Rb, or Cs) exhibit intriguing charge density wave (CDW) instabilities, which interplay with superconductivity and band topology. However, despite firm observations, the atomistic origins of the CDW phases, as well as hidden instabilities, remain elusive. Here, we adopt our newly developed symmetry-adapted cluster expansion method to construct a first-principles-based effective Hamiltonian of CsV_{3}Sb_{5}, which not only reproduces the established inverse star of David (ISD) phase, but also predict a series of D_{3h}-n states under mild tensile strains. With such atomistic Hamiltonians, the microscopic origins of different CDW states are revealed as the competition of the second-nearest neighbor V-V pairs versus the first-nearest neighbor V-V and V-Sb couplings. Interestingly, the effective Hamiltonians also reveal the existence of ionic Dzyaloshinskii-Moriya interaction in the high-symmetry phase of CsV_{3}Sb_{5} and drives the formation of noncollinear CDW patterns. Our work thus not only deepens the understanding of the CDW formation in AV_{3}Sb_{5}, but also demonstrates that the effective Hamiltonian is a suitable approach for investigating CDW mechanisms, which can be extended to various CDW systems.
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Affiliation(s)
- Binhua Zhang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Hengxin Tan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Changsong Xu
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Hongjun Xiang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
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8
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Jin F, Ren W, Tan M, Xie M, Lu B, Zhang Z, Ji J, Zhang Q. π Phase Interlayer Shift and Stacking Fault in the Kagome Superconductor CsV_{3}Sb_{5}. Phys Rev Lett 2024; 132:066501. [PMID: 38394563 DOI: 10.1103/physrevlett.132.066501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/12/2023] [Accepted: 01/19/2024] [Indexed: 02/25/2024]
Abstract
The stacking degree of freedom is a crucial factor in tuning material properties and has been extensively investigated in layered materials. The kagome superconductor CsV_{3}Sb_{5} was recently discovered to exhibit a three-dimensional CDW phase below T_{CDW}∼94 K. Despite the thorough investigation of in-plane modulation, the out-of-plane modulation has remained ambiguous. Here, our polarization- and temperature-dependent Raman measurements reveal the breaking of C_{6} rotational symmetry and the presence of three distinct domains oriented at approximately 120° to each other. The observations demonstrate that the CDW phase can be naturally explained as a 2c staggered order phase with adjacent layers exhibiting a relative π phase shift. Further, we discover a first-order structural phase transition at approximately 65 K and suggest that it is a stacking order-disorder phase transition due to stacking fault, supported by the thermal hysteresis behavior of a Cs-related phonon mode. Our findings highlight the significance of the stacking degree of freedom in CsV_{3}Sb_{5} and offer structural insights to comprehend the entanglement between superconductivity and CDW.
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Affiliation(s)
- Feng Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wei Ren
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Mingshu Tan
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Mingtai Xie
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Bingru Lu
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Zheng Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jianting Ji
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Qingming Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
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9
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Scagnoli V, Riddiford LJ, Huang SW, Shi YG, Tu Z, Lei H, Bombardi A, Nisbet G, Guguchia Z. Resonant x-ray diffraction measurements in charge ordered kagome superconductors KV 3Sb 5and RbV 3Sb 5. J Phys Condens Matter 2024; 36:185604. [PMID: 38241749 DOI: 10.1088/1361-648x/ad20a2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 01/19/2024] [Indexed: 01/21/2024]
Abstract
We report on (resonant) x-ray diffraction experiments on the normal state properties of kagome-lattice superconductors KV3Sb5and RbV3Sb5. We have confirmed previous reports indicating that the charge density wave (CDW) phase is characterized by a doubling of the unit cell in all three crystallographic directions. By monitoring the temperature dependence of Bragg peaks associated with the CDW phase, we ascertained that it develops gradually over several degrees, as opposed to CsV3Sb5, where the CDW peak intensity saturates promptly just below the CDW transition temperature. Analysis of symmetry modes indicates that this behavior arises due to lattice distortions linked to the formation of CDWs. These distortions occur abruptly in CsV3Sb5, while they progress more gradually in RbV3Sb5and KV3Sb5. In contrast, the amplitude of the mode leading to the crystallographic symmetry breaking fromP6/mmmtoFmmmappears to develop more gradually in CsV3Sb5as well. Diffraction measurements close to the V K edge and the Sb L1edge show no sensitivity to inversion- or time-symmetry breaking, which are claimed to be associated with the onset of the CDW phase. The azimuthal angle dependence of the resonant diffraction intensity observed at the Sb L1edge is associated with the difference in the population of unoccupied states and the anisotropy of the electron density of certain Sb ions.
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Affiliation(s)
- Valerio Scagnoli
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Lauren J Riddiford
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | | | - You-Guo Shi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Zhijun Tu
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, People's Republic of China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, People's Republic of China
| | - Hechang Lei
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, People's Republic of China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, People's Republic of China
| | - Alessandro Bombardi
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Gareth Nisbet
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
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10
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Hu SQ, Chen DQ, Du LL, Meng S. Solid-state high harmonic spectroscopy for all-optical band structure probing of high-pressure quantum states. Proc Natl Acad Sci U S A 2024; 121:e2316775121. [PMID: 38300874 PMCID: PMC10861900 DOI: 10.1073/pnas.2316775121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/11/2023] [Indexed: 02/03/2024] Open
Abstract
High pressure has triggered various novel states/properties in condensed matter, as the most representative and dramatic example being near-room-temperature superconductivity in highly pressured hydrides (~200 GPa). However, the mechanism of superconductivity is not confirmed, due to the lacking of effective approach to probe the electronic band structure under such high pressures. Here, we theoretically propose that the band structure and electron-phonon coupling (EPC) of high-pressure quantum states can be probed by solid-state high harmonic generation (sHHG). This strategy is investigated in high-pressure Im-3m H3S by the state-of-the-art first-principles time-dependent density-functional theory simulations, where the sHHG is revealed to be strongly dependent on the electronic structures and EPC. The dispersion of multiple bands near the Fermi level is effectively retrieved along different momentum directions. Our study provides unique insights into the potential all-optical route for band structure and EPC probing of high-pressure quantum states, which is expected to be helpful for the experimental exploration of high-pressure superconductivity in the future.
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Affiliation(s)
- Shi-Qi Hu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing100190, People’s Republic of China
| | - Da-Qiang Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing100190, People’s Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing100049, People’s Republic of China
| | - Lan-Lin Du
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing100190, People’s Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing100049, People’s Republic of China
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing100190, People’s Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing100049, People’s Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong523808, People’s Republic of China
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11
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Liu Y, Wang A, Du Q, Wu L, Zhu Y, Petrovic C. Nanoscale inhomogeneity and the evolution of correlation strength in FeSe[Formula: see text]S[Formula: see text]. Nano Converg 2023; 10:59. [PMID: 38133699 PMCID: PMC10746694 DOI: 10.1186/s40580-023-00405-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 11/26/2023] [Indexed: 12/23/2023]
Abstract
We report a comprehensive study of the nanoscale inhomogeneity and disorder on the thermoelectric properties of FeSe[Formula: see text]S[Formula: see text] ([Formula: see text]) single crystals and the evolution of correlation strength with S substitution. A hump-like feature in temperature-dependent thermpower is enhanced for x = 0.12 and 0.14 in the nematic region with increasing in orbital-selective electronic correlations, which is strongly suppressed across the nematic critical point and for higher S content. Nanoscale Se/S atom disorder in the tetrahedral surroundings of Fe atoms is confirmed by scanning transmission electron microscopy measurements, providing an insight into the nanostructural details and the evolution of correlation strength in FeSe[Formula: see text]S[Formula: see text].
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Affiliation(s)
- Yu Liu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Center for Correlated Matter and School of Physics, Zhejiang University, Hangzhou, 310058 China
| | - Aifeng Wang
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Present Address: College of Physics, Chongqing University, Chongqing, 401331 China
| | - Qianheng Du
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NeY 11790 USA
- Present Address: Material Science Division, Argonne National Laboratory, Lemont, IL 60439 USA
| | - Lijun Wu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Cedomir Petrovic
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NeY 11790 USA
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12
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Liu J, Wu WF, Wang QW, Bai XC, Zeng Z, Zou LJ. Chiral charge density wave induced by mirror symmetry breaking in kagome metal. J Phys Condens Matter 2023; 36:095601. [PMID: 37964592 DOI: 10.1088/1361-648x/ad0cae] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 11/14/2023] [Indexed: 11/16/2023]
Abstract
Kagome lattice provides a distinctive platform to investigate various correlated electron orders. Recently, an unconventional charge density wave (CDW) with novel chirality is observed in the kagome metalAV3Sb5(A= K, Rb, Cs), and the origin of which is still unclear. Here, using a tight-binding model and the mean-field method, we calculate the electron order in the quasi-two-dimensional kagome lattice with 1/3 electron filling, and show that the chiral CDW emerges under a set of parameters withC6rotational symmetry but without mirror symmetry. Physically, the reason why we choose this set of parameters is based on the possible tangential distortion of the kagome lattice. Our results provide a fresh insight to understand the microscopic origin of the unconventional CDW inAV3Sb5.
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Affiliation(s)
- Jing Liu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, PO Box 1129, Hefei 230031, People's Republic of China
| | - Wen-Feng Wu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, PO Box 1129, Hefei 230031, People's Republic of China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Qing-Wei Wang
- School of Information Engineering, Zhejiang Ocean University, Zhoushan, Zhejiang 316022, People's Republic of China
- Key Laboratory of Oceanographic Big Data Mining & Application of Zhejiang Province, Zhejiang Ocean University, Zhoushan, Zhejiang 316022, People's Republic of China
| | - Xiao-Cheng Bai
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, PO Box 1129, Hefei 230031, People's Republic of China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Zhi Zeng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, PO Box 1129, Hefei 230031, People's Republic of China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Liang-Jian Zou
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, PO Box 1129, Hefei 230031, People's Republic of China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, People's Republic of China
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13
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Abstract
Charge density wave (CDW) is a spontaneous spatial modulation of charges in solids whose general microscopic descriptions are yet to be completed. Kagome metals of AV3Sb5 (A = K, Rb, Cs) provide a chance to realize CDW intertwined with dimensional effects as well as their special lattice. Here, based on a state-of-the-art molecular dynamics simulation, we propose that their phase transition to CDW is a condensation process of incoherently preformed charge orders. Owing to unavoidable degeneracy in stacking charge orders, phases of preformed orders on each layer are shown to fluctuate between a limited number of states with quite slower frequencies than typical phonon vibrations until reaching their freezing temperature. As the size of interfacial alkali atom increases, the fluctuations are shown to counterbalance the condensation of orderings, resulting in a maximized transition temperature for RbV3Sb5. Our results resolve controversial observations on their CDWs, highlighting a crucial role of their interlayer interactions.
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Affiliation(s)
- Changwon Park
- Korea Institute for Advanced Study, Seoul, 02455, Korea
| | - Young-Woo Son
- Korea Institute for Advanced Study, Seoul, 02455, Korea.
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14
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Chen XW, Lin ZZ, Li MR. Surface-independent CO 2 and CO reduction on two-dimensional kagome metal KV 3Sb 5. Phys Chem Chem Phys 2023; 25:26081-26093. [PMID: 37740294 DOI: 10.1039/d3cp01983g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Two-dimensional kagome metals possess rich band structure characteristics, including Dirac points, flat bands, and van Hove singularities, because of their special geometric structures. Furthermore, kagome metals AV3Sb5 (A = K, Rb, and Cs) have garnered significant attention due to their nontrivial topological electronic structures. In this study, we theoretically demonstrate that the KV3Sb5 (001) surface is conducive to CO2 and CO reduction. The thermodynamic stability and electrochemical states of various surface types are investigated. The reaction paths reveal that the product is identical on different surfaces, and the free energy profiles exhibit low onset potentials. This paper elucidates the effect of two-dimensional topological kagome metals on CO2 and CO reduction.
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Affiliation(s)
- Xin-Wei Chen
- School of Physics, Xidian University, Xi'an 710071, China.
| | - Zheng-Zhe Lin
- School of Physics, Xidian University, Xi'an 710071, China.
| | - Meng-Rong Li
- School of Physics, Xidian University, Xi'an 710071, China.
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15
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Azoury D, von Hoegen A, Su Y, Oh KH, Holder T, Tan H, Ortiz BR, Capa Salinas A, Wilson SD, Yan B, Gedik N. Direct observation of the collective modes of the charge density wave in the kagome metal CsV 3Sb 5. Proc Natl Acad Sci U S A 2023; 120:e2308588120. [PMID: 37748057 PMCID: PMC10556638 DOI: 10.1073/pnas.2308588120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/31/2023] [Indexed: 09/27/2023] Open
Abstract
A recently discovered group of kagome metals AV[Formula: see text]Sb[Formula: see text] (A = K, Rb, Cs) exhibit a variety of intertwined unconventional electronic phases, which emerge from a puzzling charge density wave phase. Understanding of this charge-ordered parent phase is crucial for deciphering the entire phase diagram. However, the mechanism of the charge density wave is still controversial, and its primary source of fluctuations-the collective modes-has not been experimentally observed. Here, we use ultrashort laser pulses to melt the charge order in CsV[Formula: see text]Sb[Formula: see text] and record the resulting dynamics using femtosecond angle-resolved photoemission. We resolve the melting time of the charge order and directly observe its amplitude mode, imposing a fundamental limit for the fastest possible lattice rearrangement time. These observations together with ab initio calculations provide clear evidence for a structural rather than electronic mechanism of the charge density wave. Our findings pave the way for a better understanding of the unconventional phases hosted on the kagome lattice.
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Affiliation(s)
- Doron Azoury
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Alexander von Hoegen
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Yifan Su
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Kyoung Hun Oh
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Tobias Holder
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Hengxin Tan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Brenden R. Ortiz
- Materials Department, University of California, Santa Barbara, CA93106
| | | | - Stephen D. Wilson
- Materials Department, University of California, Santa Barbara, CA93106
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Nuh Gedik
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
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16
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Yi XW, Liao ZW, You JY, Gu B, Su G. Superconducting, Topological, and Transport Properties of Kagome Metals CsTi 3Bi 5 and RbTi 3Bi 5. Research (Wash D C) 2023; 6:0238. [PMID: 37789987 PMCID: PMC10543885 DOI: 10.34133/research.0238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/05/2023] [Indexed: 10/05/2023]
Abstract
The recently discovered ATi3Bi5 (A=Cs, Rb) exhibit intriguing quantum phenomena including superconductivity, electronic nematicity, and abundant topological states. ATi3Bi5 present promising platforms for studying kagome superconductivity, band topology, and charge orders in parallel with AV3Sb5. In this work, we comprehensively analyze various properties of ATi3Bi5 covering superconductivity under pressure and doping, band topology under pressure, thermal conductivity, heat capacity, electrical resistance, and spin Hall conductivity (SHC) using first-principles calculations. Calculated superconducting transition temperature (Tc) of CsTi3Bi5 and RbTi3Bi5 at ambient pressure are about 1.85 and 1.92 K. When subject to pressure, Tc of CsTi3Bi5 exhibits a special valley and dome shape, which arises from quasi-two-dimensional compression to three-dimensional isotropic compression within the context of an overall decreasing trend. Furthermore, Tc of RbTi3Bi5 can be effectively enhanced up to 3.09 K by tuning the kagome van Hove singularities (VHSs) and flat band through doping. Pressures can also induce abundant topological surface states at the Fermi energy (EF) and tune VHSs across EF. Additionally, our transport calculations are in excellent agreement with recent experiments, confirming the absence of charge density wave. Notably, SHC of CsTi3Bi5 can reach up to 226ℏ ·(e· Ω ·cm)-1 at EF. Our work provides a timely and detailed analysis of the rich physical properties for ATi3Bi5, offering valuable insights for further experimental verifications and investigations in this field.
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Affiliation(s)
- Xin-Wei Yi
- School of Physical Sciences,
University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng-Wei Liao
- School of Physical Sciences,
University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing-Yang You
- Department of Physics, Faculty of Science,
National University of Singapore, 117551, Singapore
| | - Bo Gu
- School of Physical Sciences,
University of Chinese Academy of Sciences, Beijing 100049, China
- Kavli Institute for Theoretical Sciences, and CAS Center for Excellence in Topological Quantum Computation,
University of Chinese Academy of Sciences, Beijing 100190, China
| | - Gang Su
- School of Physical Sciences,
University of Chinese Academy of Sciences, Beijing 100049, China
- Kavli Institute for Theoretical Sciences, and CAS Center for Excellence in Topological Quantum Computation,
University of Chinese Academy of Sciences, Beijing 100190, China
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17
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Wang Z, You JY, Chen C, Mo J, He J, Zhang L, Zhou J, Loh KP, Feng YP. Interplay of the charge density wave transition with topological and superconducting properties. Nanoscale Horiz 2023; 8:1395-1402. [PMID: 37477436 DOI: 10.1039/d3nh00207a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Exotic phenomena due to the interplay of different quantum orders have been observed and the study of these phenomena has emerged as a new frontier in condensed matter research, especially in the two-dimensional limit. Here, we report the coexistence of charge density waves (CDWs), superconductivity, and nontrivial topology in monolayer 1H-MSe2 (M = Nb, Ta) triggered by momentum-dependent electron-phonon coupling through electron doping. At a critical electron doping concentration, new 2 × 2 CDW phases emerge with nontrivial topology, Dirac cones, and van Hove singularities. Interestingly, these 2 × 2 CDW phases are also superconducting. Our findings not only reveal a route towards realizing nontrivial electronic characters by CDW engineering, but also provide an exciting platform to modulate different quantum states at the confluence of CDWs, superconductivity, nontrivial topology, and electron-phonon coupling.
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Affiliation(s)
- Zishen Wang
- Department of Physics, National University of Singapore, 117542 Singapore, Singapore.
- Centre for Advanced 2D Materials, National University of Singapore, 117546 Singapore, Singapore.
| | - Jing-Yang You
- Department of Physics, National University of Singapore, 117542 Singapore, Singapore.
| | - Chuan Chen
- Institute for Advanced Study, Tsinghua University, 100084 Beijing, China
| | - Jinchao Mo
- Department of Physics, National University of Singapore, 117542 Singapore, Singapore.
| | - Jingyu He
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China
| | - Lishu Zhang
- Department of Physics, National University of Singapore, 117542 Singapore, Singapore.
| | - Jun Zhou
- Institute of Materials Research & Engineering, A*STAR (Agency for Science, Technology and Research), 138634 Singapore, Singapore
| | - Kian Ping Loh
- Centre for Advanced 2D Materials, National University of Singapore, 117546 Singapore, Singapore.
- Department of Chemistry, National University of Singapore, 117543 Singapore, Singapore
| | - Yuan Ping Feng
- Department of Physics, National University of Singapore, 117542 Singapore, Singapore.
- Centre for Advanced 2D Materials, National University of Singapore, 117546 Singapore, Singapore.
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18
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Jiang Z, Liu Z, Ma H, Xia W, Liu Z, Liu J, Cho S, Yang Y, Ding J, Liu J, Huang Z, Qiao Y, Shen J, Jing W, Liu X, Liu J, Guo Y, Shen D. Flat bands, non-trivial band topology and rotation symmetry breaking in layered kagome-lattice RbTi 3Bi 5. Nat Commun 2023; 14:4892. [PMID: 37580381 PMCID: PMC10425367 DOI: 10.1038/s41467-023-40515-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 07/21/2023] [Indexed: 08/16/2023] Open
Abstract
A representative class of kagome materials, AV3Sb5 (A = K, Rb, Cs), hosts several unconventional phases such as superconductivity, [Formula: see text] non-trivial topological states, and electronic nematic states. These can often coexist with intertwined charge-density wave states. Recently, the discovery of the isostructural titanium-based single-crystals, ATi3Bi5 (A = K, Rb, Cs), which exhibit similar multiple exotic states but without the concomitant charge-density wave, has opened an opportunity to disentangle these complex states in kagome lattices. Here, we combine high-resolution angle-resolved photoemission spectroscopy and first-principles calculations to investigate the low-lying electronic structure of RbTi3Bi5. We demonstrate the coexistence of flat bands and several non-trivial states, including type-II Dirac nodal lines and [Formula: see text] non-trivial topological surface states. Our findings also provide evidence for rotational symmetry breaking in RbTi3Bi5, suggesting a directionality to the electronic structure and the possible emergence of pure electronic nematicity in this family of kagome compounds.
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Affiliation(s)
- Zhicheng Jiang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Zhengtai Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China.
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, 201210, Shanghai, China.
| | - Haiyang Ma
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210, Shanghai, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210, Shanghai, China
| | - Zhonghao Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Jishan Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, 201210, Shanghai, China
| | - Soohyun Cho
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Yichen Yang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Jianyang Ding
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Jiayu Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Zhe Huang
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Yuxi Qiao
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Jiajia Shen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Wenchuan Jing
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Xiangqi Liu
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210, Shanghai, China
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 230029, Hefei, China
| | - Jianpeng Liu
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210, Shanghai, China.
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210, Shanghai, China.
| | - Dawei Shen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China.
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 230029, Hefei, China.
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19
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Tan H, Li Y, Liu Y, Kaplan D, Wang Z, Yan B. Emergent topological quantum orbits in the charge density wave phase of kagome metal CsV 3Sb 5. NPJ Quantum Mater 2023; 8:39. [PMID: 38666241 PMCID: PMC11041708 DOI: 10.1038/s41535-023-00571-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/15/2023] [Indexed: 04/28/2024]
Abstract
The recently discovered kagome materials AV3Sb5 (A = K, Rb, Cs) attract intense research interest in intertwined topology, superconductivity, and charge density waves (CDW). Although the in-plane 2 × 2 CDW is well studied, its out-of-plane structural correlation with the Fermi surface properties is less understood. In this work, we advance the theoretical description of quantum oscillations and investigate the Fermi surface properties in the three-dimensional CDW phase of CsV3Sb5. We derived Fermi-energy-resolved and layer-resolved quantum orbits that agree quantitatively with recent experiments in the fundamental frequency, cyclotron mass, and topology. We reveal a complex Dirac nodal network that would lead to a π Berry phase of a quantum orbit in the spinless case. However, the phase shift of topological quantum orbits is contributed by the orbital moment and Zeeman effect besides the Berry phase in the presence of spin-orbital coupling (SOC). Therefore, we can observe topological quantum orbits with a π phase shift in otherwise trivial orbits without SOC, contrary to common perception. Our work reveals the rich topological nature of kagome materials and paves a path to resolve different topological origins of quantum orbits.
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Affiliation(s)
- Hengxin Tan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - Yongkang Li
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - Yizhou Liu
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - Daniel Kaplan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, MA 02467 USA
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001 Israel
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20
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Sur Y, Kim KT, Kim S, Kim KH. Optimized superconductivity in the vicinity of a nematic quantum critical point in the kagome superconductor Cs(V 1-xTi x) 3Sb 5. Nat Commun 2023; 14:3899. [PMID: 37414793 DOI: 10.1038/s41467-023-39495-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/06/2023] [Indexed: 07/08/2023] Open
Abstract
CsV3Sb5 exhibits superconductivity at Tc = 3.2 K after undergoing intriguing two high-temperature transitions: charge density wave order at ~98 K and electronic nematic order at Tnem ~ 35 K. Here, we investigate nematic susceptibility in single crystals of Cs(V1-xTix)3Sb5 (x = 0.00-0.06) where double-dome-shaped superconducting phase diagram is realized. The nematic susceptibility typically exhibits the Curie‒Weiss behaviour above Tnem, which is monotonically decreased with x. Moreover, the Curie‒Weiss temperature is systematically suppressed from ~30 K for x = 0 to ~4 K for x = 0.0075, resulting in a sign change at x = ~0.009. Furthermore, the Curie constant reaches a maximum at x = 0.01, suggesting drastically enhanced nematic susceptibility near a putative nematic quantum critical point (NQCP) at x = ~0.009. Strikingly, Tc is enhanced up to ~4.1 K with full Meissner shielding realized at x = ~0.0075-0.01, forming the first superconducting dome near the NQCP. Our findings directly point to a vital role of nematic fluctuations in enhancing the superconducting properties of Cs(V1-xTix)3Sb5.
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Affiliation(s)
- Yeahan Sur
- Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kwang-Tak Kim
- Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sukho Kim
- Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kee Hoon Kim
- Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea.
- Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea.
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21
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Jiang Z, Ma H, Xia W, Liu Z, Xiao Q, Liu Z, Yang Y, Ding J, Huang Z, Liu J, Qiao Y, Liu J, Peng Y, Cho S, Guo Y, Liu J, Shen D. Observation of Electronic Nematicity Driven by the Three-Dimensional Charge Density Wave in Kagome Lattice KV 3Sb 5. Nano Lett 2023. [PMID: 37310876 DOI: 10.1021/acs.nanolett.3c01151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Kagome superconductors AV3Sb5 (A = K, Rb, Cs) provide a fertile playground for studying intriguing phenomena, including nontrivial band topology, superconductivity, giant anomalous Hall effect, and charge density wave (CDW). Recently, a C2 symmetric nematic phase prior to the superconducting state in AV3Sb5 drew enormous attention due to its potential inheritance of the symmetry of the unusual superconductivity. However, direct evidence of the rotation symmetry breaking of the electronic structure in the CDW state from the reciprocal space is still rare, and the underlying mechanism remains ambiguous. The observation shows unconventional unidirectionality, indicative of rotation symmetry breaking from six-fold to two-fold. The interlayer coupling between adjacent planes with π-phase offset in the 2 × 2 × 2 CDW phase leads to the preferred two-fold symmetric electronic structure. These rarely observed unidirectional back-folded bands in KV3Sb5 may provide important insights into its peculiar charge order and superconductivity.
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Affiliation(s)
- Zhicheng Jiang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haiyang Ma
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210 Shanghai, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210 Shanghai, China
| | - Zhengtai Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qian Xiao
- International Center for Quantum Materials, School of Physics, Peking University, 100871 Beijing, China
| | - Zhonghao Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yichen Yang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianyang Ding
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhe Huang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Jiayu Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuxi Qiao
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jishan Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingying Peng
- International Center for Quantum Materials, School of Physics, Peking University, 100871 Beijing, China
| | - Soohyun Cho
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210 Shanghai, China
| | - Jianpeng Liu
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210 Shanghai, China
| | - Dawei Shen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 42 South Hezuohua Road, Hefei, Anhui 230029, China
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22
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Guo Y, Qiu D, Shao M, Song J, Wang Y, Xu M, Yang C, Li P, Liu H, Xiong J. Modulations in Superconductors: Probes of Underlying Physics. Adv Mater 2023; 35:e2209457. [PMID: 36504310 DOI: 10.1002/adma.202209457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/16/2022] [Indexed: 06/02/2023]
Abstract
The importance of modulations is elevated to an unprecedented level, due to the delicate conditions required to bring out exotic phenomena in quantum materials, such as topological materials, magnetic materials, and superconductors. Recently, state-of-the-art modulation techniques in material science, such as electric-double-layer transistor, piezoelectric-based strain apparatus, angle twisting, and nanofabrication, have been utilized in superconductors. They not only efficiently increase the tuning capability to the broader ranges but also extend the tuning dimensionality to unprecedented degrees of freedom, including quantum fluctuations of competing phases, electronic correlation, and phase coherence essential to global superconductivity. Here, for a comprehensive review, these techniques together with the established modulation methods, such as elemental substitution, annealing, and polarization-induced gating, are contextualized. Depending on the mechanism of each method, the modulations are categorized into stoichiometric manipulation, electrostatic gating, mechanical modulation, and geometrical design. Their recent advances are highlighted by applications in newly discovered superconductors, e.g., nickelates, Kagome metals, and magic-angle graphene. Overall, the review is to provide systematic modulations in emergent superconductors and serve as the coordinate for future investigations, which can stimulate researchers in superconductivity and other fields to perform various modulations toward a thorough understanding of quantum materials.
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Affiliation(s)
- Yehao Guo
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Dong Qiu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Mingxin Shao
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Jingyan Song
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yang Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Minyi Xu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Chao Yang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Peng Li
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Haiwen Liu
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Jie Xiong
- State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, China
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23
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Song B, Ying T, Wu X, Xia W, Yin Q, Zhang Q, Song Y, Yang X, Guo J, Gu L, Chen X, Hu J, Schnyder AP, Lei H, Guo Y, Li S. Anomalous enhancement of charge density wave in kagome superconductor CsV 3Sb 5 approaching the 2D limit. Nat Commun 2023; 14:2492. [PMID: 37120572 PMCID: PMC10148882 DOI: 10.1038/s41467-023-38257-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 04/17/2023] [Indexed: 05/01/2023] Open
Abstract
The recently discovered kagome metals AV3Sb5 (A = Cs, Rb, K) exhibit a variety of intriguing phenomena, such as a charge density wave (CDW) with time-reversal symmetry breaking and possible unconventional superconductivity. Here, we report a rare non-monotonic evolution of the CDW temperature (TCDW) with the reduction of flake thickness approaching the atomic limit, and the superconducting transition temperature (Tc) features an inverse variation with TCDW. TCDW initially decreases to a minimum value of 72 K at 27 layers and then increases abruptly, reaching a record-high value of 120 K at 5 layers. Raman scattering measurements reveal a weakened electron-phonon coupling with the reduction of sample thickness, suggesting that a crossover from electron-phonon coupling to dominantly electronic interactions could account for the non-monotonic thickness dependence of TCDW. Our work demonstrates the novel effects of dimension reduction and carrier doping on quantum states in thin flakes and provides crucial insights into the complex mechanism of the CDW order in the family of AV3Sb5 kagome metals.
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Affiliation(s)
- Boqin Song
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai, 200433, China
| | - Tianping Ying
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Xianxin Wu
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai, 201210, China
| | - Qiangwei Yin
- Laboratory for Neutron Scattering, and Beijing Key Laboratory of Optoelectronic Functional Materials MicroNano Devices, Department of Physics, Renmin University of China, Beijing, 100872, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yanpeng Song
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaofan Yang
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai, 200433, China
| | - Jiangang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaolong Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jiangping Hu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Andreas P Schnyder
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany
| | - Hechang Lei
- Laboratory for Neutron Scattering, and Beijing Key Laboratory of Optoelectronic Functional Materials MicroNano Devices, Department of Physics, Renmin University of China, Beijing, 100872, China.
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Shiyan Li
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai, 200433, China.
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, China.
- Shanghai Research Center for Quantum Sciences, Shanghai, 201315, China.
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24
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Zhong Y, Liu J, Wu X, Guguchia Z, Yin JX, Mine A, Li Y, Najafzadeh S, Das D, Mielke C, Khasanov R, Luetkens H, Suzuki T, Liu K, Han X, Kondo T, Hu J, Shin S, Wang Z, Shi X, Yao Y, Okazaki K. Nodeless electron pairing in CsV 3Sb 5-derived kagome superconductors. Nature 2023; 617:488-492. [PMID: 37100906 DOI: 10.1038/s41586-023-05907-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 03/01/2023] [Indexed: 04/28/2023]
Abstract
The newly discovered kagome superconductors represent a promising platform for investigating the interplay between band topology, electronic order and lattice geometry1-9. Despite extensive research efforts on this system, the nature of the superconducting ground state remains elusive10-17. In particular, consensus on the electron pairing symmetry has not been achieved so far18-20, in part owing to the lack of a momentum-resolved measurement of the superconducting gap structure. Here we report the direct observation of a nodeless, nearly isotropic and orbital-independent superconducting gap in the momentum space of two exemplary CsV3Sb5-derived kagome superconductors-Cs(V0.93Nb0.07)3Sb5 and Cs(V0.86Ta0.14)3Sb5-using ultrahigh-resolution and low-temperature angle-resolved photoemission spectroscopy. Remarkably, such a gap structure is robust to the appearance or absence of charge order in the normal state, tuned by isovalent Nb/Ta substitutions of V. Our comprehensive characterizations of the superconducting gap provide indispensable information on the electron pairing symmetry of kagome superconductors, and advance our understanding of the superconductivity and intertwined electronic orders in quantum materials.
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Affiliation(s)
- Yigui Zhong
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan
| | - Jinjin Liu
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, China
| | - Xianxin Wu
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, China
| | - Zurab Guguchia
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - J-X Yin
- Laboratory for Quantum Emergence, Department of Physics, Southern University of Science and Technology, Shenzhen, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen, China
| | - Akifumi Mine
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan
| | - Yongkai Li
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, China
- Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, China
| | - Sahand Najafzadeh
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan
| | - Debarchan Das
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Charles Mielke
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Rustem Khasanov
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Hubertus Luetkens
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Takeshi Suzuki
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan
| | - Kecheng Liu
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan
| | - Xinloong Han
- Kavli Institute of Theoretical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Takeshi Kondo
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan
- Trans-scale Quantum Science Institute, The University of Tokyo, Tokyo, Japan
| | - Jiangping Hu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Shik Shin
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan
- Office of University Professor, The University of Tokyo, Kashiwa, Japan
| | - Zhiwei Wang
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China.
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, China.
- Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, China.
| | - Xun Shi
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China.
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, China.
| | - Yugui Yao
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing, China
- Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, China
| | - Kozo Okazaki
- Institute for Solid States Physics, The University of Tokyo, Kashiwa, Japan.
- Trans-scale Quantum Science Institute, The University of Tokyo, Tokyo, Japan.
- Material Innovation Research Center, The University of Tokyo, Kashiwa, Japan.
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25
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Zhong Y, Li S, Liu H, Dong Y, Aido K, Arai Y, Li H, Zhang W, Shi Y, Wang Z, Shin S, Lee HN, Miao H, Kondo T, Okazaki K. Testing electron-phonon coupling for the superconductivity in kagome metal CsV 3Sb 5. Nat Commun 2023; 14:1945. [PMID: 37029104 PMCID: PMC10082024 DOI: 10.1038/s41467-023-37605-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 03/23/2023] [Indexed: 04/09/2023] Open
Abstract
In crystalline materials, electron-phonon coupling (EPC) is a ubiquitous many-body interaction that drives conventional Bardeen-Cooper-Schrieffer superconductivity. Recently, in a new kagome metal CsV3Sb5, superconductivity that possibly intertwines with time-reversal and spatial symmetry-breaking orders is observed. Density functional theory calculations predicted weak EPC strength, λ, supporting an unconventional pairing mechanism in CsV3Sb5. However, experimental determination of λ is still missing, hindering a microscopic understanding of the intertwined ground state of CsV3Sb5. Here, using 7-eV laser-based angle-resolved photoemission spectroscopy and Eliashberg function analysis, we determine an intermediate λ=0.45-0.6 at T = 6 K for both Sb 5p and V 3d electronic bands, which can support a conventional superconducting transition temperature on the same magnitude of experimental value in CsV3Sb5. Remarkably, the EPC on the V 3d-band enhances to λ~0.75 as the superconducting transition temperature elevated to 4.4 K in Cs(V0.93Nb0.07)3Sb5. Our results provide an important clue to understand the pairing mechanism in the kagome superconductor CsV3Sb5.
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Affiliation(s)
- Yigui Zhong
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Shaozhi Li
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Hongxiong Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Yuyang Dong
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Kohei Aido
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Yosuke Arai
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Haoxiang Li
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Advanced Materials Thrust, The Hong Kong University of Science and Technology (Guangzhou), 511453, Guangzhou, Guangdong, China
| | - Weilu Zhang
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
- Department of Engineering and Applied Sciences, Sophia University, Tokyo, 102-8554, Japan
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA
| | - Shik Shin
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
- Office of University Professor, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - H N Lee
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - H Miao
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| | - Takeshi Kondo
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan.
- Trans-scale Quantum Science Institute, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan.
| | - Kozo Okazaki
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan.
- Trans-scale Quantum Science Institute, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan.
- Material Innovation Research Center, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan.
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26
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Chapai R, Leroux M, Oliviero V, Vignolles D, Bruyant N, Smylie MP, Chung DY, Kanatzidis MG, Kwok WK, Mitchell JF, Welp U. Magnetic Breakdown and Topology in the Kagome Superconductor CsV_{3}Sb_{5} under High Magnetic Field. Phys Rev Lett 2023; 130:126401. [PMID: 37027842 DOI: 10.1103/physrevlett.130.126401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/15/2022] [Accepted: 03/03/2023] [Indexed: 06/19/2023]
Abstract
The recently discovered layered kagome metals of composition AV_{3}Sb_{5} (A=K, Rb, Cs) exhibit a complex interplay among superconductivity, charge density wave order, topologically nontrivial electronic band structure and geometrical frustration. Here, we probe the electronic band structure underlying these exotic correlated electronic states in CsV_{3}Sb_{5} with quantum oscillation measurements in pulsed fields up to 86 T. The high-field data reveal a sequence of magnetic breakdown orbits that allows the construction of a model for the folded Fermi surface of CsV_{3}Sb_{5}. The dominant features are large triangular Fermi surface sheets that cover almost half the folded Brillouin zone. These sheets have not yet been detected in angle resolved photoemission spectroscopy and display pronounced nesting. The Berry phases of the electron orbits have been deduced from Landau level fan diagrams near the quantum limit without the need for extrapolations, thereby unambiguously establishing the nontrivial topological character of several electron bands in this kagome lattice superconductor.
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Affiliation(s)
- Ramakanta Chapai
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Maxime Leroux
- LNCMI-EMFL, CNRS UPR3228, Université Grenoble Alpes, Université de Toulouse, Université de Toulouse 3, INSA-T, Grenoble and Toulouse, France
| | - Vincent Oliviero
- LNCMI-EMFL, CNRS UPR3228, Université Grenoble Alpes, Université de Toulouse, Université de Toulouse 3, INSA-T, Grenoble and Toulouse, France
| | - David Vignolles
- LNCMI-EMFL, CNRS UPR3228, Université Grenoble Alpes, Université de Toulouse, Université de Toulouse 3, INSA-T, Grenoble and Toulouse, France
| | - Nicolas Bruyant
- LNCMI-EMFL, CNRS UPR3228, Université Grenoble Alpes, Université de Toulouse, Université de Toulouse 3, INSA-T, Grenoble and Toulouse, France
| | - M P Smylie
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
- Department of Physics and Astronomy, Hofstra University, Hempstead, New York 11549, USA
| | - D Y Chung
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - M G Kanatzidis
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
- Department of Chemistry, Northwestern University, Evanston, Illinois 60201, USA
| | - W-K Kwok
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - J F Mitchell
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ulrich Welp
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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27
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Yin JX. Quantum dephasing of kagome superconductivity. Sci Bull (Beijing) 2023; 68:568-570. [PMID: 36872206 DOI: 10.1016/j.scib.2023.02.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Affiliation(s)
- Jia-Xin Yin
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China; Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen 518045, China.
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28
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Wen X, Yu F, Gui Z, Zhang Y, Hou X, Shan L, Wu T, Xiang Z, Wang Z, Ying J, Chen X. Emergent superconducting fluctuations in compressed kagome superconductor CsV 3Sb 5. Sci Bull (Beijing) 2023; 68:259-265. [PMID: 36681589 DOI: 10.1016/j.scib.2023.01.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/18/2022] [Accepted: 01/16/2023] [Indexed: 01/19/2023]
Abstract
The recent discovery of superconductivity (SC) and charge density wave (CDW) in kagome metals AV3Sb5 (A = K, Rb, Cs) provides an ideal playground for the study of emergent electronic orders. Application of moderate pressure leads to a two-dome-shaped SC phase regime in CsV3Sb5 accompanied by the destabilizing of CDW phase. Nonetheless, the nature of this pressure-tuned SC state and its interplay with the CDW are yet to be explored. Here, we perform soft point-contact spectroscopy (SPCS) measurements in CsV3Sb5 to investigate the evolution of superconducting order parameter with pressure. Surprisingly, we find that the superconducting gap is significantly enhanced between the two SC domes, at which the zero-resistance temperature is suppressed and the transition is remarkably broadened. Moreover, the temperature-dependence of the SC gap in this pressure range severely deviates from the conventional Bardeen-Cooper-Schrieffer (BCS) behavior, evidencing for strong Cooper pair phase fluctuations. These findings reveal the complex intertwining of the CDW with SC in the compressed CsV3Sb5, suggesting striking parallel to the cuprate superconductor La2-xBaxCuO4. Our results point to the essential role of charge degree of freedom in the development of intertwining electronic orders, and thus provide new constraints for theories.
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Affiliation(s)
- Xikai Wen
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
| | - Fanghang Yu
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zhigang Gui
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yuqing Zhang
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xingyuan Hou
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Lei Shan
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China; Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei 230601, China
| | - Tao Wu
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ziji Xiang
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zhenyu Wang
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jianjun Ying
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China.
| | - Xianhui Chen
- Department of Physics, and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China; CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei 230026, China.
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29
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Zheng G, Tan C, Chen Z, Wang M, Zhu X, Albarakati S, Algarni M, Partridge J, Farrar L, Zhou J, Ning W, Tian M, Fuhrer MS, Wang L. Electrically controlled superconductor-to-failed insulator transition and giant anomalous Hall effect in kagome metal CsV(3)Sb(5) nanoflakes. Nat Commun 2023; 14:678. [PMID: 36755031 DOI: 10.1038/s41467-023-36208-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 01/18/2023] [Indexed: 02/10/2023] Open
Abstract
The electronic correlations (e.g. unconventional superconductivity (SC), chiral charge order and nematic order) and giant anomalous Hall effect (AHE) in topological kagome metals AV3Sb5 (A = K, Rb, and Cs) have attracted great interest. Electrical control of those correlated electronic states and AHE allows us to resolve their own nature and origin and to discover new quantum phenomena. Here, we show that electrically controlled proton intercalation has significant impacts on striking quantum phenomena in CsV3Sb5 nanodevices mainly through inducing disorders in thinner nanoflakes and carrier density modulation in thicker ones. Specifically, in disordered thin nanoflakes (below 25 nm), we achieve a quantum phase transition from a superconductor to a "failed insulator" with a large saturated sheet resistance for T → 0 K. Meanwhile, the carrier density modulation in thicker nanoflakes shifts the Fermi level across the charge density wave (CDW) gap and gives rise to an extrinsic-intrinsic transition of AHE. With the first-principles calculations, the extrinsic skew scattering of holes in the nearly flat bands with finite Berry curvature by multiple impurities would account for the giant AHE. Our work uncovers a distinct disorder-driven bosonic superconductor-insulator transition (SIT), outlines a global picture of the giant AHE and reveals its correlation with the unconventional CDW in the AV3Sb5 family.
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30
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Zhang W, Liu X, Wang L, Tsang CW, Wang Z, Lam ST, Wang W, Xie J, Zhou X, Zhao Y, Wang S, Tallon J, Lai KT, Goh SK. Nodeless Superconductivity in Kagome Metal CsV 3Sb 5 with and without Time Reversal Symmetry Breaking. Nano Lett 2023; 23:872-879. [PMID: 36662599 PMCID: PMC9912374 DOI: 10.1021/acs.nanolett.2c04103] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/13/2023] [Indexed: 06/17/2023]
Abstract
The kagome metal CsV3Sb5 features an unusual competition between the charge-density-wave (CDW) order and superconductivity. Evidence for time reversal symmetry breaking (TRSB) inside the CDW phase has been accumulating. Hence, the superconductivity in CsV3Sb5 emerges from a TRSB normal state, potentially resulting in an exotic superconducting state. To reveal the pairing symmetry, we first investigate the effect of nonmagnetic impurity. Our results show that the superconducting critical temperature is insensitive to disorder, pointing to conventional s-wave superconductivity. Moreover, our measurements of the self-field critical current (Ic,sf), which is related to the London penetration depth, also confirm conventional s-wave superconductivity with strong coupling. Finally, we measure Ic,sf where the CDW order is removed by pressure and superconductivity emerges from the pristine normal state. Our results show that s-wave gap symmetry is retained, providing strong evidence for the presence of conventional s-wave superconductivity in CsV3Sb5 irrespective of the presence of the TRSB.
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Affiliation(s)
- Wei Zhang
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Xinyou Liu
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Lingfei Wang
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Chun Wai Tsang
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Zheyu Wang
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Siu Tung Lam
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Wenyan Wang
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Jianyu Xie
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
| | - Xuefeng Zhou
- Department
of Physics, Southern University of Science
and Technology, Shenzhen, Guangdong518055, China
| | - Yusheng Zhao
- Department
of Physics, Southern University of Science
and Technology, Shenzhen, Guangdong518055, China
| | - Shanmin Wang
- Department
of Physics, Southern University of Science
and Technology, Shenzhen, Guangdong518055, China
| | - Jeff Tallon
- Robinson
Institute, Victoria University of Wellington, P.O. Box 600, Wellington6140, New Zealand
| | - Kwing To Lai
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
- Shenzhen
Research Institute, The Chinese University
of Hong Kong, Shatin, Hong Kong, China
| | - Swee K. Goh
- Department
of Physics, The Chinese University of Hong
Kong, Shatin, Hong Kong, China
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31
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Roppongi M, Ishihara K, Tanaka Y, Ogawa K, Okada K, Liu S, Mukasa K, Mizukami Y, Uwatoko Y, Grasset R, Konczykowski M, Ortiz BR, Wilson SD, Hashimoto K, Shibauchi T. Bulk evidence of anisotropic s-wave pairing with no sign change in the kagome superconductor CsV(3)Sb(5). Nat Commun 2023; 14:667. [PMID: 36750576 DOI: 10.1038/s41467-023-36273-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/16/2023] [Indexed: 02/09/2023] Open
Abstract
The recently discovered kagome superconductors AV3Sb5 (A = K, Rb, Cs) exhibit unusual charge-density-wave (CDW) orders with time-reversal and rotational symmetry breaking. One of the most crucial unresolved issues is identifying the symmetry of the superconductivity that develops inside the CDW phase. Theory predicts a variety of unconventional superconducting symmetries with sign-changing and chiral order parameters. Experimentally, however, superconducting phase information in AV3Sb5 is still lacking. Here we report the impurity effects in CsV3Sb5 using electron irradiation as a phase-sensitive probe of superconductivity. Our magnetic penetration depth measurements reveal that with increasing impurities, an anisotropic fully-gapped state changes to an isotropic full-gap state without passing through a nodal state. Furthermore, transport measurements under pressure show that the double superconducting dome in the pressure-temperature phase diagram survives against sufficient impurities. These results support that CsV3Sb5 is a non-chiral, anisotropic s-wave superconductor with no sign change both at ambient and under pressure.
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32
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Scammell HD, Ingham J, Li T, Sushkov OP. Chiral excitonic order from twofold van Hove singularities in kagome metals. Nat Commun 2023; 14:605. [PMID: 36739274 PMCID: PMC9899280 DOI: 10.1038/s41467-023-35987-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 01/10/2023] [Indexed: 02/06/2023] Open
Abstract
Recent experiments on kagome metals AV3Sb5 (A=K,Rb,Cs) identify twofold van Hove singularities (TvHS) with opposite concavity near the Fermi energy, generating two approximately hexagonal Fermi surfaces - one electron-like and the other hole-like. Here we propose that a TvHS generates a novel time-reversal symmetry breaking excitonic order - arising due to bound pairs of electrons and holes located at opposite concavity van Hove singularities. We introduce a minimal model for the TvHS and investigate interaction induced many-body instabilities via the perturbative renormalisation group technique and a free energy analysis. Specialising to parameters appropriate for the kagome metals AV3Sb5, we construct a phase diagram comprising chiral excitons, charge density wave and a region of coexistence. We propose this as an explanation of a diverse range of experimental observations in AV3Sb5. Notably, the chiral excitonic state gives rise to a quantum anomalous Hall conductance, providing an appealing interpretation of the observed anomalous Hall effect in kagome metals. Possible alternative realisations of the TvHS mechanism in bilayer materials are also discussed. We suggest that TvHS open up interesting possibilities for correlated phases, enriching the set of competing ground states to include excitonic order.
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Affiliation(s)
- Harley D. Scammell
- grid.1005.40000 0004 4902 0432School of Physics, University of New South Wales, Sydney, NSW 2052 Australia ,grid.1005.40000 0004 4902 0432Australian Research Council Centre of Excellence in Future Low-Energy Electronics Technologies, University of New South Wales, Sydney, NSW 2052 Australia
| | - Julian Ingham
- grid.189504.10000 0004 1936 7558Physics Department, Boston University, Commonwealth Avenue, Boston, MA 02215 USA
| | - Tommy Li
- grid.14095.390000 0000 9116 4836Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Oleg P. Sushkov
- grid.1005.40000 0004 4902 0432School of Physics, University of New South Wales, Sydney, NSW 2052 Australia ,grid.1005.40000 0004 4902 0432Australian Research Council Centre of Excellence in Future Low-Energy Electronics Technologies, University of New South Wales, Sydney, NSW 2052 Australia
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33
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Jiang K, Wu T, Yin JX, Wang Z, Hasan MZ, Wilson SD, Chen X, Hu J. Kagome superconductors AV 3Sb 5 (A = K, Rb, Cs). Natl Sci Rev 2023; 10:nwac199. [PMID: 36935933 PMCID: PMC10016199 DOI: 10.1093/nsr/nwac199] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 01/20/2022] [Accepted: 02/14/2022] [Indexed: 11/14/2022] Open
Abstract
The quasi-two-dimensional kagome materials AV3Sb5 (A = K, Rb, Cs) were found to be a prime example of kagome superconductors, a new quantum platform to investigate the interplay between electron correlation effects, topology and geometric frustration. In this review, we report recent progress on the experimental and theoretical studies of AV3Sb5 and provide a broad picture of this fast-developing field in order to stimulate an expanded search for unconventional kagome superconductors. We review the electronic properties of AV3Sb5, the experimental measurements of the charge density wave state, evidence of time-reversal symmetry breaking and other potential hidden symmetry breaking in these materials. A variety of theoretical proposals and models that address the nature of the time-reversal symmetry breaking are discussed. Finally, we review the superconducting properties of AV3Sb5, especially the potential pairing symmetries and the interplay between superconductivity and the charge density wave state.
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Affiliation(s)
- Kun Jiang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Tao Wu
- Corresponding author. E-mail:
| | | | - Zhenyu Wang
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei 230026, China
| | - M Zahid Hasan
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Stephen D Wilson
- Materials Department and California Nanosystems Institute, University of California Santa Barbara, Santa Barbara, CA 93106, USA
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34
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Kang M, Fang S, Yoo J, Ortiz BR, Oey YM, Choi J, Ryu SH, Kim J, Jozwiak C, Bostwick A, Rotenberg E, Kaxiras E, Checkelsky JG, Wilson SD, Park JH, Comin R. Charge order landscape and competition with superconductivity in kagome metals. Nat Mater 2023; 22:186-193. [PMID: 36329264 DOI: 10.1038/s41563-022-01375-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
In the kagome metals AV3Sb5 (A = K, Rb, Cs), three-dimensional charge order is the primary instability that sets the stage for other collective orders to emerge, including unidirectional stripe order, orbital flux order, electronic nematicity and superconductivity. Here, we use high-resolution angle-resolved photoemission spectroscopy to determine the microscopic structure of three-dimensional charge order in AV3Sb5 and its interplay with superconductivity. Our approach is based on identifying an unusual splitting of kagome bands induced by three-dimensional charge order, which provides a sensitive way to refine the spatial charge patterns in neighbouring kagome planes. We found a marked dependence of the three-dimensional charge order structure on composition and doping. The observed difference between CsV3Sb5 and the other compounds potentially underpins the double-dome superconductivity in CsV3(Sb,Sn)5 and the suppression of Tc in KV3Sb5 and RbV3Sb5. Our results provide fresh insights into the rich phase diagram of AV3Sb5.
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Affiliation(s)
- Mingu Kang
- Center for Complex Phase of Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea.
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Shiang Fang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jonggyu Yoo
- Center for Complex Phase of Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Brenden R Ortiz
- Materials Department, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Yuzki M Oey
- Materials Department, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Jonghyeok Choi
- Center for Complex Phase of Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sae Hee Ryu
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jimin Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Republic of Korea
| | - Chris Jozwiak
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Aaron Bostwick
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Eli Rotenberg
- Advanced Light Source, E. O. Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Efthimios Kaxiras
- Department of Physics, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Joseph G Checkelsky
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Stephen D Wilson
- Materials Department, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Jae-Hoon Park
- Center for Complex Phase of Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea.
- Department of Physics, Pohang University of Science and Technology, Pohang, Republic of Korea.
| | - Riccardo Comin
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
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35
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Han S, Tang CS, Li L, Liu Y, Liu H, Gou J, Wu J, Zhou D, Yang P, Diao C, Ji J, Bao J, Zhang L, Zhao M, Milošević MV, Guo Y, Tian L, Breese MBH, Cao G, Cai C, Wee ATS, Yin X. Orbital-Hybridization-Driven Charge Density Wave Transition in CsV 3 Sb 5 Kagome Superconductor. Adv Mater 2023; 35:e2209010. [PMID: 36468620 DOI: 10.1002/adma.202209010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Owing to its inherent non-trivial geometry, the unique structural motif of the recently discovered kagome topological superconductor AV3 Sb5 (A = K, Rb, Cs) is an ideal host of diverse topologically non-trivial phenomena, including giant anomalous Hall conductivity, topological charge order, charge density wave (CDW), and unconventional superconductivity. Despite possessing a normal-state CDW order in the form of topological chiral charge order and diverse superconducting gaps structures, it remains unclear how fundamental atomic-level properties and many-body effects including Fermi surface nesting, electron-phonon coupling, and orbital hybridization contribute to these symmetry-breaking phenomena. Here, the direct participation of the V3d-Sb5p orbital hybridization in mediating the CDW phase transition in CsV3 Sb5 is reported. The combination of temperature-dependent X-ray absorption and first-principles studies clearly indicates the inverse Star-of-David structure as the preferred reconstruction in the low-temperature CDW phase. The results highlight the critical role that Sb orbitals play and establish orbital hybridization as the direct mediator of the CDW states and structural transition dynamics in kagome unconventional superconductors. This is a significant step toward the fundamental understanding and control of the emerging correlated phases from the kagome lattice through the orbital interactions and provides promising approaches to novel regimes in unconventional orders and topology.
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Affiliation(s)
- Shulun Han
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Chi Sin Tang
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
- The Singapore Synchrotron Light Source (SSLS), National University of Singapore, Singapore, 117603, Singapore
| | - Linyang Li
- School of Science, Hebei University of Technology, Tianjin, 300401, P. R. China
| | - Yi Liu
- Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, P. R. China
| | - Huimin Liu
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Jian Gou
- Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research, National University of Singapore, Singapore, 117546, Singapore
| | - Jing Wu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A∗STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Difan Zhou
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Ping Yang
- The Singapore Synchrotron Light Source (SSLS), National University of Singapore, Singapore, 117603, Singapore
| | - Caozheng Diao
- The Singapore Synchrotron Light Source (SSLS), National University of Singapore, Singapore, 117603, Singapore
| | - Jiacheng Ji
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Jinke Bao
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Lingfeng Zhang
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Mingwen Zhao
- School of Physics, Shandong University, Jinan, 250100, P. R. China
| | - Milorad V Milošević
- Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, Antwerpen, B-2020, Belgium
| | - Yanqun Guo
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Lijun Tian
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Mark B H Breese
- The Singapore Synchrotron Light Source (SSLS), National University of Singapore, Singapore, 117603, Singapore
- Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542, Singapore
| | - Guanghan Cao
- Department of Physics, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Chuanbing Cai
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
| | - Andrew T S Wee
- Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research, National University of Singapore, Singapore, 117546, Singapore
| | - Xinmao Yin
- Shanghai Key Laboratory of High Temperature Superconductors, Shanghai Frontiers Science Center of Quantum and Superconducting Matter States, Physics Department, Shanghai University, Shanghai, 200444, P. R. China
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36
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Guguchia Z, Mielke C 3rd, Das D, Gupta R, Yin JX, Liu H, Yin Q, Christensen MH, Tu Z, Gong C, Shumiya N, Hossain MS, Gamsakhurdashvili T, Elender M, Dai P, Amato A, Shi Y, Lei HC, Fernandes RM, Hasan MZ, Luetkens H, Khasanov R. Tunable unconventional kagome superconductivity in charge ordered RbV(3)Sb(5) and KV(3)Sb(5). Nat Commun 2023; 14:153. [PMID: 36631467 DOI: 10.1038/s41467-022-35718-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/15/2022] [Indexed: 01/12/2023] Open
Abstract
Unconventional superconductors often feature competing orders, small superfluid density, and nodal electronic pairing. While unusual superconductivity has been proposed in the kagome metals AV3Sb5, key spectroscopic evidence has remained elusive. Here we utilize pressure-tuned and ultra-low temperature muon spin spectroscopy to uncover the unconventional nature of superconductivity in RbV3Sb5 and KV3Sb5. At ambient pressure, we observed time-reversal symmetry breaking charge order below [Formula: see text] 110 K in RbV3Sb5 with an additional transition at [Formula: see text] 50 K. Remarkably, the superconducting state displays a nodal energy gap and a reduced superfluid density, which can be attributed to the competition with the charge order. Upon applying pressure, the charge-order transitions are suppressed, the superfluid density increases, and the superconducting state progressively evolves from nodal to nodeless. Once optimal superconductivity is achieved, we find a superconducting pairing state that is not only fully gapped, but also spontaneously breaks time-reversal symmetry. Our results point to unprecedented tunable nodal kagome superconductivity competing with time-reversal symmetry-breaking charge order and offer unique insights into the nature of the pairing state.
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37
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Yi XW, Liao ZW, You JY, Gu B, Su G. Topological superconductivity and large spin Hall effect in the kagome family Ti 6X 4 (X = Bi, Sb, Pb, Tl, and In). iScience 2022; 26:105813. [PMID: 36619974 PMCID: PMC9817178 DOI: 10.1016/j.isci.2022.105813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/29/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Topological superconductors (TSC) become a focus of research due to the accompanying Majorana fermions. However, the reported TSC are extremely rare. Recent experiments reported kagome TSC AV3Sb5 (A = K, Rb, and Cs) exhibit unique superconductivity, topological surface states (TSS), and Majorana bound states. More recently, the first titanium-based kagome superconductor CsTi3Bi5 with nontrivial topology was successfully synthesized as a perspective TSC. Given that Cs contributes little to electronic structures of CsTi3Bi5 and binary compounds may be easier to be synthesized, here, by first-principle calculations, we predict five stable nonmagnetic kagome compounds Ti6X4 (X = Bi, Sb, Pb, Tl, and In) which exhibit superconductivity with critical temperature Tc = 3.8 K - 5.1 K, nontrivial Z 2 band topology, and TSS close to the Fermi level. Additionally, large intrinsic spin Hall effect is obtained in Ti6X4, which is caused by gapped Dirac nodal lines due to a strong spin-orbit coupling. This work offers new platforms for TSC and spintronic devices.
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Affiliation(s)
- Xin-Wei Yi
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng-Wei Liao
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing-Yang You
- Department of Physics, Faculty of Science, National University of Singapore, Singapore 117551, Singapore,Corresponding author
| | - Bo Gu
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China,Kavli Institute for Theoretical Sciences, CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China,Corresponding author
| | - Gang Su
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China,Kavli Institute for Theoretical Sciences, CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China,Corresponding author
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38
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Abstract
A kagome lattice naturally features Dirac fermions, flat bands and van Hove singularities in its electronic structure. The Dirac fermions encode topology, flat bands favour correlated phenomena such as magnetism, and van Hove singularities can lead to instabilities towards long-range many-body orders, altogether allowing for the realization and discovery of a series of topological kagome magnets and superconductors with exotic properties. Recent progress in exploring kagome materials has revealed rich emergent phenomena resulting from the quantum interactions between geometry, topology, spin and correlation. Here we review these key developments in this field, starting from the fundamental concepts of a kagome lattice, to the realizations of Chern and Weyl topological magnetism, to various flat-band many-body correlations, and then to the puzzles of unconventional charge-density waves and superconductivity. We highlight the connection between theoretical ideas and experimental observations, and the bond between quantum interactions within kagome magnets and kagome superconductors, as well as their relation to the concepts in topological insulators, topological superconductors, Weyl semimetals and high-temperature superconductors. These developments broadly bridge topological quantum physics and correlated many-body physics in a wide range of bulk materials and substantially advance the frontier of topological quantum matter.
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39
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Kato T, Li Y, Nakayama K, Wang Z, Souma S, Matsui F, Kitamura M, Horiba K, Kumigashira H, Takahashi T, Yao Y, Sato T. Fermiology and Origin of T_{c} Enhancement in a Kagome Superconductor Cs(V_{1-x}Nb_{x})_{3}Sb_{5}. Phys Rev Lett 2022; 129:206402. [PMID: 36461993 DOI: 10.1103/physrevlett.129.206402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/14/2022] [Accepted: 10/06/2022] [Indexed: 06/17/2023]
Abstract
Kagome metals AV_{3}Sb_{5} (A=K, Rb, and Cs) exhibit a characteristic superconducting ground state coexisting with a charge density wave (CDW), whereas the mechanisms of the superconductivity and CDW have yet to be clarified. Here we report a systematic angle-resolved photoemission spectroscopy (ARPES) study of Cs(V_{1-x}Nb_{x})_{3}Sb_{5} as a function of Nb content x, where isovalent Nb substitution causes an enhancement of superconducting transition temperature (T_{c}) and the reduction of CDW temperature (T_{CDW}). We found that the Nb substitution shifts the Sb-derived electron band at the Γ point downward and simultaneously moves the V-derived band around the M point upward to lift up the saddle point (SP) away from the Fermi level, leading to the reduction of the CDW-gap magnitude and T_{CDW}. This indicates a primary role of the SP density of states to stabilize the CDW. The present result also suggests that the enhancement of superconductivity by Nb substitution is caused by the cooperation between the expansion of the Sb-derived electron pocket and the recovery of the V-derived density of states at the Fermi level.
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Affiliation(s)
- Takemi Kato
- Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Yongkai Li
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing 314011, People's Republic of China
| | - Kosuke Nakayama
- Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Tokyo 102-0076, Japan
| | - Zhiwei Wang
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing 314011, People's Republic of China
| | - Seigo Souma
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai 980-8577, Japan
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
| | - Fumihiko Matsui
- UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
| | - Miho Kitamura
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Koji Horiba
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- National Institutes for Quantum Science and Technology (QST), Sendai 980-8579, Japan
| | - Hiroshi Kumigashira
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai 980-8577, Japan
| | - Takashi Takahashi
- Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai 980-8577, Japan
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
| | - Yugui Yao
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Takafumi Sato
- Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai 980-8577, Japan
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577, Japan
- International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University, Sendai 980-8577, Japan
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40
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Zheng L, Wu Z, Yang Y, Nie L, Shan M, Sun K, Song D, Yu F, Li J, Zhao D, Li S, Kang B, Zhou Y, Liu K, Xiang Z, Ying J, Wang Z, Wu T, Chen X. Emergent charge order in pressurized kagome superconductor CsV 3Sb 5. Nature 2022; 611:682-687. [PMID: 36418450 DOI: 10.1038/s41586-022-05351-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 09/15/2022] [Indexed: 11/24/2022]
Abstract
The discovery of several electronic orders in kagome superconductors AV3Sb5 (A means K, Rb, Cs) provides a promising platform for exploring unprecedented emergent physics1-9. Under moderate pressure (<2.2 GPa), the triple-Q charge density wave (CDW) order is monotonically suppressed by pressure, while the superconductivity shows a two-dome-like behaviour, suggesting an unusual interplay between superconductivity and CDW order10,11. Given that time-reversal symmetry breaking and electronic nematicity have been revealed inside the triple-Q CDW phase8,9,12,13, understanding this CDW order and its interplay with superconductivity becomes one of the core questions in AV3Sb5 (refs. 3,5,6). Here, we report the evolution of CDW and superconductivity with pressure in CsV3Sb5 by 51V nuclear magnetic resonance measurements. An emergent CDW phase, ascribed to a possible stripe-like CDW order with a unidirectional 4a0 modulation, is observed between Pc1 ≅ 0.58 GPa and Pc2 ≅ 2.0 GPa, which explains the two-dome-like superconducting behaviour under pressure. Furthermore, the nuclear spin-lattice relaxation measurement reveals evidence for pressure-independent charge fluctuations above the CDW transition temperature and unconventional superconducting pairing above Pc2. Our results not only shed new light on the interplay of superconductivity and CDW, but also reveal new electronic correlation effects in kagome superconductors AV3Sb5.
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Affiliation(s)
- Lixuan Zheng
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Zhimian Wu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Ye Yang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Linpeng Nie
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Min Shan
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Kuanglv Sun
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Dianwu Song
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Fanghang Yu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Jian Li
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Dan Zhao
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Shunjiao Li
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Baolei Kang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Yanbing Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Kai Liu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Ziji Xiang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China.,CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, China
| | - Jianjun Ying
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, China
| | - Zhenyu Wang
- CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, China.,CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai, China
| | - Tao Wu
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China. .,CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, China. .,CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai, China. .,Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China. .,Hefei National Laboratory, University of Science and Technology of China, Hefei, China.
| | - Xianhui Chen
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China. .,CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, China. .,CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai, China. .,Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China. .,Hefei National Laboratory, University of Science and Technology of China, Hefei, China.
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41
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Chen X, Fei G, Song Y, Ying T, Huang D, Pan B, Yang D, Yang X, Chen K, Zhan X, Wang J, Zhang Q, Li Y, Gu L, Gou H, Chen X, Li S, Cheng J, Liu X, Hosono H, Guo JG, Chen X. Superatomic-Charge-Density-Wave in Cluster-Assembled Au 6Te 12Se 8 Superconductors. J Am Chem Soc 2022; 144:20915-20922. [DOI: 10.1021/jacs.2c09499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xu Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ge Fei
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, China
| | - Yanpeng Song
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Tianping Ying
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Dajian Huang
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Bingying Pan
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China
| | - Dongliang Yang
- Beijing Synchrotron Radiation Facility Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaofan Yang
- State Key Laboratory of Surface Physics, Department of Physics, and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China
| | - Keyu Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xinhui Zhan
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, China
| | - Junjie Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yanchun Li
- Beijing Synchrotron Radiation Facility Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Huiyang Gou
- Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China
| | - Xin Chen
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, China
| | - Shiyan Li
- State Key Laboratory of Surface Physics, Department of Physics, and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, China
| | - Jinguang Cheng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaobing Liu
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, China
| | - Hideo Hosono
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503, Japan
| | - Jian-gang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Xiaolong Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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42
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Li H, Fabbris G, Said AH, Sun JP, Jiang YX, Yin JX, Pai YY, Yoon S, Lupini AR, Nelson CS, Yin QW, Gong CS, Tu ZJ, Lei HC, Cheng JG, Hasan MZ, Wang Z, Yan B, Thomale R, Lee HN, Miao H. Discovery of conjoined charge density waves in the kagome superconductor CsV 3Sb 5. Nat Commun 2022; 13:6348. [PMID: 36289236 PMCID: PMC9606281 DOI: 10.1038/s41467-022-33995-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 10/07/2022] [Indexed: 11/09/2022] Open
Abstract
The electronic instabilities in CsV3Sb5 are believed to originate from the V 3d-electrons on the kagome plane, however the role of Sb 5p-electrons for 3-dimensional orders is largely unexplored. Here, using resonant tender X-ray scattering and high-pressure X-ray scattering, we report a rare realization of conjoined charge density waves (CDWs) in CsV3Sb5, where a 2 × 2 × 1 CDW in the kagome sublattice and a Sb 5p-electron assisted 2 × 2 × 2 CDW coexist. At ambient pressure, we discover a resonant enhancement on Sb L1-edge (2s→5p) at the 2 × 2 × 2 CDW wavevectors. The resonance, however, is absent at the 2 × 2 × 1 CDW wavevectors. Applying hydrostatic pressure, CDW transition temperatures are separated, where the 2 × 2 × 2 CDW emerges 4 K above the 2 × 2 × 1 CDW at 1 GPa. These observations demonstrate that symmetry-breaking phases in CsV3Sb5 go beyond the minimal framework of kagome electronic bands near van Hove filling.
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Affiliation(s)
- Haoxiang Li
- grid.135519.a0000 0004 0446 2659Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA ,grid.24515.370000 0004 1937 1450Present Address: Advanced Materials Thrust, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou, Guangdong 511453 China
| | - G. Fabbris
- grid.187073.a0000 0001 1939 4845Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 USA
| | - A. H. Said
- grid.187073.a0000 0001 1939 4845Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 USA
| | - J. P. Sun
- grid.9227.e0000000119573309Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China ,grid.410726.60000 0004 1797 8419School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190 China
| | - Yu-Xiao Jiang
- grid.16750.350000 0001 2097 5006Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ 08544 USA
| | - J.-X. Yin
- grid.263817.90000 0004 1773 1790Laboratory for Quantum Emergence, Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong 518055 China
| | - Yun-Yi Pai
- grid.135519.a0000 0004 0446 2659Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Sangmoon Yoon
- grid.135519.a0000 0004 0446 2659Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA ,grid.256155.00000 0004 0647 2973Present Address: Department of Physics, Gachon University, Seongnam, 13120 Republic of Korea
| | - Andrew R. Lupini
- grid.135519.a0000 0004 0446 2659Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - C. S. Nelson
- grid.202665.50000 0001 2188 4229National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Q. W. Yin
- grid.24539.390000 0004 0368 8103Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Microdevices, Renmin University of China, Beijing, 100872 China
| | - C. S. Gong
- grid.24539.390000 0004 0368 8103Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Microdevices, Renmin University of China, Beijing, 100872 China
| | - Z. J. Tu
- grid.24539.390000 0004 0368 8103Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Microdevices, Renmin University of China, Beijing, 100872 China
| | - H. C. Lei
- grid.24539.390000 0004 0368 8103Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Microdevices, Renmin University of China, Beijing, 100872 China
| | - J.-G. Cheng
- grid.9227.e0000000119573309Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 China ,grid.410726.60000 0004 1797 8419School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190 China
| | - M. Z. Hasan
- grid.16750.350000 0001 2097 5006Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ 08544 USA
| | - Ziqiang Wang
- grid.208226.c0000 0004 0444 7053Department of Physics, Boston College, Chestnut Hill, MA 02467 USA
| | - Binghai Yan
- grid.13992.300000 0004 0604 7563Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - R. Thomale
- grid.8379.50000 0001 1958 8658Institute for Theoretical Physics, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - H. N. Lee
- grid.135519.a0000 0004 0446 2659Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - H. Miao
- grid.135519.a0000 0004 0446 2659Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
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43
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Zhang X, Hou J, Xia W, Xu Z, Yang P, Wang A, Liu Z, Shen J, Zhang H, Dong X, Uwatoko Y, Sun J, Wang B, Guo Y, Cheng J. Destabilization of the Charge Density Wave and the Absence of Superconductivity in ScV 6Sn 6 under High Pressures up to 11 GPa. Materials (Basel) 2022; 15:7372. [PMID: 36295437 PMCID: PMC9611248 DOI: 10.3390/ma15207372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/05/2022] [Accepted: 10/08/2022] [Indexed: 06/16/2023]
Abstract
RV6Sn6 (R = Sc, Y, or rare earth) is a new family of kagome metals that have a similar vanadium structural motif as AV3Sb5 (A = K, Rb, Cs) compounds. Unlike AV3Sb5, ScV6Sn6 is the only compound among the series of RV6Sn6 that displays a charge density wave (CDW) order at ambient pressure, yet it shows no superconductivity (SC) at low temperatures. Here, we perform a high-pressure transport study on the ScV6Sn6 single crystal to track the evolutions of the CDW transition and to explore possible SC. In contrast to AV3Sb5 compounds, the CDW order of ScV6Sn6 can be suppressed completely by a pressure of about 2.4 GPa, but no SC is detected down to 40 mK at 2.35 GPa and 1.5 K up to 11 GPa. Moreover, we observed that the resistivity anomaly around the CDW transition undergoes an obvious change at ~2.04 GPa before it vanishes completely. The present work highlights a distinct relationship between CDW and SC in ScV6Sn6 in comparison with the well-studied AV3Sb5.
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Affiliation(s)
- Xiaoxiao Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Hou
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Wei Xia
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai Tech University, Shanghai 201210, China
| | - Zhian Xu
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
| | - Pengtao Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Anqi Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Ziyi Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jie Shen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hua Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoli Dong
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Yoshiya Uwatoko
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Chiba, Japan
| | - Jianping Sun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Bosen Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Yanfeng Guo
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai Tech University, Shanghai 201210, China
| | - Jinguang Cheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
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44
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Broyles C, Graf D, Yang H, Dong X, Gao H, Ran S. Effect of the Interlayer Ordering on the Fermi Surface of Kagome Superconductor CsV_{3}Sb_{5} Revealed by Quantum Oscillations. Phys Rev Lett 2022; 129:157001. [PMID: 36269950 DOI: 10.1103/physrevlett.129.157001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 08/08/2022] [Accepted: 09/01/2022] [Indexed: 06/16/2023]
Abstract
The connection between unconventional superconductivity and charge density waves (CDWs) has intrigued the condensed matter community and found much interest in the recently discovered superconducting Kagome family of AV_{3}Sb_{5} (A=K, Cs, Rb). X-ray diffraction and Raman spectroscopy measurements established that the CDW order in CsV_{3}Sb_{5} comprises of a 2×2×4 structure with stacking of layers in a star-of-David (SD) and inverse-star-of-David (ISD) pattern along the c-axis direction. Such interlayer ordering will induce a vast normalization of the electronic ground state; however, it has not been observed in Fermi surface measurements. Here we report quantum oscillations of CsV_{3}Sb_{5} using tunnel diode oscillator frequency measurements. We observed a large number of frequencies, many of which were not reported. The number of frequencies cannot be explained by DFT calculations when only SD or ISD distortion is considered. Instead, our results are consistent with calculations when interlayer ordering is taken into account, providing strong evidence that the CDW phase of CsV_{3}Sb_{5} has complicated structure distortion which in turn has dramatic effects on the Fermi surface properties.
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Affiliation(s)
- Christopher Broyles
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - David Graf
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - Haitao Yang
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xiaoli Dong
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Hongjun Gao
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Sheng Ran
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130, USA
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Yang H, Huang Z, Zhang Y, Zhao Z, Shi J, Luo H, Zhao L, Qian G, Tan H, Hu B, Zhu K, Lu Z, Zhang H, Sun J, Cheng J, Shen C, Lin X, Yan B, Zhou X, Wang Z, Pennycook SJ, Chen H, Dong X, Zhou W, Gao HJ. Titanium doped kagome superconductor CsV3−Ti Sb5 and two distinct phases. Sci Bull (Beijing) 2022; 67:2176-2185. [DOI: 10.1016/j.scib.2022.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/11/2022]
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46
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Chen Q, Chen D, Schnelle W, Felser C, Gaulin BD. Charge Density Wave Order and Fluctuations above T_{CDW} and below Superconducting T_{c} in the Kagome Metal CsV_{3}Sb_{5}. Phys Rev Lett 2022; 129:056401. [PMID: 35960582 DOI: 10.1103/physrevlett.129.056401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/31/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
The phase diagram of the kagome metal family AV_{3}Sb_{5} (A=K, Rb, Cs) features both superconductivity and charge density wave (CDW) instabilities, which have generated tremendous recent attention. Nonetheless, significant questions remain. In particular, the temperature evolution and demise of the CDW state has not been extensively studied, and little is known about the coexistence of the CDW with superconductivity at low temperatures. We report an x-ray scattering study of CsV_{3}Sb_{5} over a broad range of temperatures from 300 to ∼2 K, below the onset of its superconductivity at T_{c}∼2.9 K. Order parameter measurements of the 2×2×2 CDW structure show an unusual and extended linear temperature dependence onsetting at T^{*}∼160 K, much higher than the susceptibility anomaly associated with CDW order at T_{CDW}=94 K. This implies strong CDW fluctuations exist to ∼1.7×T_{CDW}. The CDW order parameter is observed to be constant from T=16 to 2 K, implying that the CDW and superconducting order coexist below T_{c}, and, at ambient pressure, any possible competition between the two order parameters is manifested at temperatures well below T_{c}, if at all. Anomalies in the temperature dependence in the lattice parameters coincide with T_{CDW} for c(T) and with T^{*} for a(T).
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Affiliation(s)
- Q Chen
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Brockhouse Institute for Materials Research, Hamilton, Ontario L8S 4M1, Canada
| | - D Chen
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- College of Physics, Qingdao University, Qingdao 266071, China
| | - W Schnelle
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - C Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Canadian Institute for Advanced Research, Toronto, Ontario M5G 1M1, Canada
| | - B D Gaulin
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Brockhouse Institute for Materials Research, Hamilton, Ontario L8S 4M1, Canada
- Canadian Institute for Advanced Research, Toronto, Ontario M5G 1M1, Canada
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Abstract
Based on the hybrid functional, we find that at 0 GPa, pristine CsV3Sb5 has a magnetic moment of 0.28 μB per vanadium atom, which is suppressed at a pressure of 2.5 GPa resulting in a spin-crossover. Since the ground state of CsV3Sb5 with charge density wave (CDW) distortion is a non-magnetic state, the magnetic moment of V atoms in pristine CsV3Sb5 will be suppressed by the temperature-induced CDW transition at 94 K. The schematic evolution of magnetic moments as functions of pressure and temperature is presented. At low temperature, CsV3Sb5 is a rare example of materials hosting a pressure-induced magnetic moment, and we suggest that the effects of magnetic moments of V atoms should be considered for understanding its properties.
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Affiliation(s)
- Wenfeng Wu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China. .,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China
| | - Xianlong Wang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China. .,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China
| | - Zhi Zeng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China. .,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China
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48
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Shi M, Yu F, Yang Y, Meng F, Lei B, Luo Y, Sun Z, He J, Wang R, Jiang Z, Liu Z, Shen D, Wu T, Wang Z, Xiang Z, Ying J, Chen X. A new class of bilayer kagome lattice compounds with Dirac nodal lines and pressure-induced superconductivity. Nat Commun 2022; 13:2773. [PMID: 35589799 DOI: 10.1038/s41467-022-30442-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/27/2022] [Indexed: 11/08/2022] Open
Abstract
Kagome lattice composed of transition-metal ions provides a great opportunity to explore the intertwining between geometry, electronic orders and band topology. The discovery of multiple competing orders that connect intimately with the underlying topological band structure in nonmagnetic kagome metals AV3Sb5 (A = K, Rb, Cs) further pushes this topic to the quantum frontier. Here we report a new class of vanadium-based compounds with kagome bilayers, namely AV6Sb6 (A = K, Rb, Cs) and V6Sb4, which, together with AV3Sb5, compose a series of kagome compounds with a generic chemical formula (Am-1Sb2m)(V3Sb)n (m = 1, 2; n = 1, 2). Theoretical calculations combined with angle-resolved photoemission measurements reveal that these compounds feature Dirac nodal lines in close vicinity to the Fermi level. Pressure-induced superconductivity in AV6Sb6 further suggests promising emergent phenomena in these materials. The establishment of a new family of layered kagome materials paves the way for designer of fascinating kagome systems with diverse topological nontrivialities and collective ground states.
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49
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Liu ZY, Dong QX, Yang PT, Shan PF, Wang BS, Sun JP, Dun ZL, Uwatoko Y, Chen GF, Dong XL, Zhao ZX, Cheng JG. Pressure-Induced Superconductivity up to 9 K in the Quasi-One-Dimensional KMn_{6}Bi_{5}. Phys Rev Lett 2022; 128:187001. [PMID: 35594110 DOI: 10.1103/physrevlett.128.187001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/13/2022] [Accepted: 04/07/2022] [Indexed: 06/15/2023]
Abstract
The Mn-based superconductor is rare owing to the strong magnetic pair-breaking effect. Here we report on the discovery of pressure-induced superconductivity in KMn_{6}Bi_{5}, which becomes the first ternary Mn-based superconductor. At ambient pressure, the quasi-one-dimensional KMn_{6}Bi_{5} is an antiferromagnetic metal with T_{N}≈75 K. By measuring resistance and ac magnetic susceptibility under hydrostatic pressures up to 14.2 GPa in a cubic anvil cell apparatus, we find that its antiferromagnetic transition can be suppressed completely at a critical pressure of P_{c}≈13 GPa, around which bulk superconductivity emerges and displays a superconducting dome with the maximal T_{c}^{onset}=9.3 K achieved at about 14 GPa. The close proximity of superconductivity to a magnetic instability in the temperature-pressure phase diagram of KMn_{6}Bi_{5} and an unusually large μ_{0}H_{c2}(0) exceeding the Pauli paramagnetic limit suggests an unconventional magnetism-mediated paring mechanism. In contrast to the binary MnP, the flexibility of the crystal structure and chemical compositions in the ternary AMn_{6}Bi_{5} (A=alkali metal) can open a new avenue for finding more Mn-based superconductors.
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Affiliation(s)
- Z Y Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Q X Dong
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - P T Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - P F Shan
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - B S Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - J P Sun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Z L Dun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Y Uwatoko
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - G F Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - X L Dong
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Z X Zhao
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - J-G Cheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
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50
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Hu Y, Wu X, Ortiz BR, Ju S, Han X, Ma J, Plumb NC, Radovic M, Thomale R, Wilson SD, Schnyder AP, Shi M. Rich nature of Van Hove singularities in Kagome superconductor CsV 3Sb 5. Nat Commun 2022; 13:2220. [PMID: 35468883 DOI: 10.1038/s41467-022-29828-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/30/2022] [Indexed: 11/16/2022] Open
Abstract
The recently discovered layered kagome metals AV3Sb5 (A = K, Rb, Cs) exhibit diverse correlated phenomena, which are intertwined with a topological electronic structure with multiple van Hove singularities (VHSs) in the vicinity of the Fermi level. As the VHSs with their large density of states enhance correlation effects, it is of crucial importance to determine their nature and properties. Here, we combine polarization-dependent angle-resolved photoemission spectroscopy with density functional theory to directly reveal the sublattice properties of 3d-orbital VHSs in CsV3Sb5. Four VHSs are identified around the M point and three of them are close to the Fermi level, with two having sublattice-pure and one sublattice-mixed nature. Remarkably, the VHS just below the Fermi level displays an extremely flat dispersion along MK, establishing the experimental discovery of higher-order VHS. The characteristic intensity modulation of Dirac cones around K further demonstrates the sublattice interference embedded in the kagome Fermiology. The crucial insights into the electronic structure, revealed by our work, provide a solid starting point for the understanding of the intriguing correlation phenomena in the kagome metals AV3Sb5. Predictions suggest enhanced correlation effect due to multiple van Hove singularities (VHS) in the vicinity of the Fermi level in the recently discovered AV3Sb5 kagome metals. Here the authors identify three VHSs close to the Fermi level with diverse sublattice characters in CsV3Sb5, and one of them shows flat dispersion suggesting the higher-order nature.
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