1
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Yoshizawa S, Sagisaka K, Sakata H. Visualization of Alternating Triangular Domains of Charge Density Waves in 2H-NbSe_{2} by Scanning Tunneling Microscopy. PHYSICAL REVIEW LETTERS 2024; 132:056401. [PMID: 38364174 DOI: 10.1103/physrevlett.132.056401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 10/27/2023] [Accepted: 12/21/2023] [Indexed: 02/18/2024]
Abstract
The charge density wave (CDW) state of 2H-NbSe_{2} features commensurate domains separated by domain boundaries accompanied by phase slips known as discommensurations. We have unambiguously visualized the structure of CDW domains using a displacement-field measurement algorithm on a scanning tunneling microscopy image. Each CDW domain is delimited by three vertices and three edges of discommensurations and is designated by a triplet of integers whose sum identifies the types of commensurate structure. The observed structure is consistent with the alternating triangular tiling pattern predicted by a phenomenological Landau theory. The domain shape is affected by crystal defects and also by topological defects in the CDW phase factor. Our results provide a foundation for a complete understanding of the CDW state and its relation to the superconducting state.
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Affiliation(s)
- Shunsuke Yoshizawa
- Center for Basic Research on Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Keisuke Sagisaka
- Center for Basic Research on Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Hideaki Sakata
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
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2
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Liu YB, Zhou J, Wu C, Yang F. Charge-4e superconductivity and chiral metal in 45°-twisted bilayer cuprates and related bilayers. Nat Commun 2023; 14:7926. [PMID: 38040764 PMCID: PMC10692084 DOI: 10.1038/s41467-023-43782-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 11/20/2023] [Indexed: 12/03/2023] Open
Abstract
The material realization of charge-4e/6e superconductivity (SC) is a big challenge. Here, we propose to realize charge-4e SC in maximally-twisted homobilayers, such as 45∘-twisted bilayer cuprates and 30∘-twisted bilayer graphene, referred to as twist-bilayer quasicrystals (TB-QC). When each monolayer hosts a pairing state with the largest pairing angular momentum, previous studies have found that the second-order interlayer Josephson coupling would drive chiral topological SC (TSC) in the TB-QC. Here we propose that, above the Tc of the chiral TSC, either charge-4e SC or chiral metal can arise as vestigial phases, depending on the ordering of the total- and relative-pairing-phase fields of the two layers. Based on a thorough symmetry analysis to get the low-energy effective Hamiltonian, we conduct a combined renormalization-group and Monte-Carlo study and obtain the phase diagram, which includes the charge-4e SC and chiral metal phases.
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Affiliation(s)
- Yu-Bo Liu
- School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Jing Zhou
- Department of Science, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
- Institute for Advanced Sciences, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
| | - Congjun Wu
- Institute for Theoretical Sciences, WestLake University, 310024, Hangzhou, China
- New Cornerstone Science Laboratory, Department of Physics, School of Science, Westlake University, 310024, Hangzhou, China
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, Hangzhou, 310030, P. R. China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, P. R. China
| | - Fan Yang
- School of Physics, Beijing Institute of Technology, Beijing, 100081, China.
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3
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Lee S, Kim E, Bang J, Park J, Kim C, Wulferding D, Cho D. Melting of Unidirectional Charge Density Waves across Twin Domain Boundaries in GdTe 3. NANO LETTERS 2023. [PMID: 38019157 DOI: 10.1021/acs.nanolett.3c03721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Solids undergoing a transition from order to disorder experience a proliferation of topological defects. The melting process generates transient quantum states. However, their dynamic nature with a femtosecond lifetime hinders exploration with atomic precision. Here, we suggest an alternative approach to the dynamic melting process by focusing on the interface created by competing degenerate quantum states. We use a scanning tunneling microscope (STM) to visualize the unidirectional charge density wave (CDW) and its spatial progression ("static melting") across a twin domain boundary (TDB) in the layered material GdTe3. Combining the STM with a spatial lock-in technique, we reveal that the order parameter amplitude attenuates with the formation of dislocations and thus two different unidirectional CDWs coexist near the TDB, reducing the CDW anisotropy. Notably, we discovered a correlation between this anisotropy and the CDW gap. Our study provides valuable insight into the behavior of topological defects and transient quantum states.
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Affiliation(s)
- Sanghun Lee
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Eunseo Kim
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Junho Bang
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
| | - Jongho Park
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Changyoung Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Dirk Wulferding
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Doohee Cho
- Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
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4
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Shen X, Heid R, Hott R, Haghighirad AA, Salzmann B, Dos Reis Cantarino M, Monney C, Said AH, Frachet M, Murphy B, Rossnagel K, Rosenkranz S, Weber F. Precursor region with full phonon softening above the charge-density-wave phase transition in 2H-TaSe 2. Nat Commun 2023; 14:7282. [PMID: 37949889 PMCID: PMC10638379 DOI: 10.1038/s41467-023-43094-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023] Open
Abstract
Research on charge-density-wave (CDW) ordered transition-metal dichalcogenides continues to unravel new states of quantum matter correlated to the intertwined lattice and electronic degrees of freedom. Here, we report an inelastic x-ray scattering investigation of the lattice dynamics of the canonical CDW compound 2H-TaSe2 complemented by angle-resolved photoemission spectroscopy and density functional perturbation theory. Our results rule out the formation of a central-peak without full phonon softening for the CDW transition in 2H-TaSe2 and provide evidence for a novel precursor region above the CDW transition temperature TCDW, which is characterized by an overdamped phonon mode and not detectable in our photoemission experiments. Thus, 2H-TaSe2 exhibits structural before electronic static order and emphasizes the important lattice contribution to CDW transitions. Our ab-initio calculations explain the interplay of electron-phonon coupling and Fermi surface topology triggering the CDW phase transition and predict that the CDW soft phonon mode promotes emergent superconductivity near the pressure-driven CDW quantum critical point.
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Affiliation(s)
- Xingchen Shen
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- College of Physics, Chongqing University, Chongqing, 401331, P. R. China
| | - Rolf Heid
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Roland Hott
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Amir-Abbas Haghighirad
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Björn Salzmann
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Marli Dos Reis Cantarino
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
- Instituto de Física, Universidade de São Paulo, São Paulo, São Paulo, 05508-090, Brazil
| | - Claude Monney
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Ayman H Said
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Mehdi Frachet
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Bridget Murphy
- Institute of Experimental and Applied Physics and KiNSIS, Kiel University, 24098, Kiel, Germany
- Ruprecht Haensel Laboratory, Kiel University, 24098, Kiel, Germany
| | - Kai Rossnagel
- Institute of Experimental and Applied Physics and KiNSIS, Kiel University, 24098, Kiel, Germany
- Ruprecht Haensel Laboratory, Kiel University, 24098, Kiel, Germany
- Ruprecht Haensel Laboratory, Deutsches Elektronen-Synchrotron DESY, 22607, Hamburg, Germany
| | - Stephan Rosenkranz
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Frank Weber
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany.
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5
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Ji H, Liu Y, Li Y, Ding X, Xie Z, Ji C, Qi S, Gao X, Xu M, Gao P, Qiao L, Yang YF, Zhang GM, Wang J. Rotational symmetry breaking in superconducting nickelate Nd 0.8Sr 0.2NiO 2 films. Nat Commun 2023; 14:7155. [PMID: 37935701 PMCID: PMC10630465 DOI: 10.1038/s41467-023-42988-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 10/25/2023] [Indexed: 11/09/2023] Open
Abstract
The infinite-layer nickelates, isostructural to the high-Tc cuprate superconductors, have emerged as a promising platform to host unconventional superconductivity and stimulated growing interest in the condensed matter community. Despite considerable attention, the superconducting pairing symmetry of the nickelate superconductors, the fundamental characteristic of a superconducting state, is still under debate. Moreover, the strong electronic correlation in the nickelates may give rise to a rich phase diagram, where the underlying interplay between the superconductivity and other emerging quantum states with broken symmetry is awaiting exploration. Here, we study the angular dependence of the transport properties of the infinite-layer nickelate Nd0.8Sr0.2NiO2 superconducting films with Corbino-disk configuration. The azimuthal angular dependence of the magnetoresistance (R(φ)) manifests the rotational symmetry breaking from isotropy to four-fold (C4) anisotropy with increasing magnetic field, revealing a symmetry-breaking phase transition. Approaching the low-temperature and large-magnetic-field regime, an additional two-fold (C2) symmetric component in the R(φ) curves and an anomalous upturn of the temperature-dependent critical field are observed simultaneously, suggesting the emergence of an exotic electronic phase. Our work uncovers the evolution of the quantum states with different rotational symmetries in nickelate superconductors and provides deep insight into their global phase diagram.
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Affiliation(s)
- Haoran Ji
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Yi Liu
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Yanan Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Xiang Ding
- School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Zheyuan Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Chengcheng Ji
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Shichao Qi
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Xiaoyue Gao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871, China
| | - Minghui Xu
- School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Peng Gao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871, China
| | - Liang Qiao
- School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China.
| | - Yi-Feng 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, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Guang-Ming Zhang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China
- Frontier Science Center for Quantum Information, Beijing, 100084, China
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China.
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China.
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
- Hefei National Laboratory, Hefei, 230088, China.
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6
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Ma L, Wang X, Wang H, Wang X, Zou G, Guan Y, Guo S, Li H, Chen Q, Kang L, Zhang L, Wu P. van der Waals Self-Epitaxial Growth of Inch-Sized Superconducting Niobium Diselenide Films. NANO LETTERS 2023; 23:6892-6899. [PMID: 37470724 DOI: 10.1021/acs.nanolett.3c01283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Ultrathin superconducting films are the basis of superconductor devices. van der Waals (vdW) NbSe2 with noncentrosymmetry exhibits exotic superconductivity and shows promise in superconductor electronic devices. However, the growth of inch-scale NbSe2 films with layer regulation remains a challenge because vdW structural material growth is strongly dependent on the epitaxial guidance of the substrate. Herein, a vdW self-epitaxy strategy is developed to eliminate the substrate driving force in film growth and realize inch-sized NbSe2 film growth with thicknesses from 2.1 to 12.1 nm on arbitrary substrates. The superconducting transition temperature of 5.1 K and superconducting transition width of 0.30 K prove the top homogeneity and quality of superconductivity among all of the synthetic NbSe2 films. Coupled with a large area and substrate compatibility, this work paves the way for developing NbSe2 superconductor electronics.
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Affiliation(s)
- Liang Ma
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
| | - Xiaohan Wang
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
| | - Hao Wang
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
- Hefei National Laboratory, Hefei 230088, China
| | - Xiangyi Wang
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123, China
| | - Guifu Zou
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123, China
| | - Yanqiu Guan
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
| | - Shuya Guo
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
| | - Haochen Li
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
| | - Qi Chen
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
| | - Lin Kang
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
- Hefei National Laboratory, Hefei 230088, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Labao Zhang
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
- Hefei National Laboratory, Hefei 230088, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Peiheng Wu
- Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210023, China
- Hefei National Laboratory, Hefei 230088, China
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7
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Wang X, Wang H, Ma L, Zhang L, Yang Z, Dong D, Chen X, Li H, Guan Y, Zhang B, Chen Q, Shi L, Li H, Qin Z, Tu X, Zhang L, Jia X, Chen J, Kang L, Wu P. Topotactic fabrication of transition metal dichalcogenide superconducting nanocircuits. Nat Commun 2023; 14:4282. [PMID: 37463894 DOI: 10.1038/s41467-023-39997-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 07/07/2023] [Indexed: 07/20/2023] Open
Abstract
Superconducting nanocircuits, which are usually fabricated from superconductor films, are the core of superconducting electronic devices. While emerging transition-metal dichalcogenide superconductors (TMDSCs) with exotic properties show promise for exploiting new superconducting mechanisms and applications, their environmental instability leads to a substantial challenge for the nondestructive preparation of TMDSC nanocircuits. Here, we report a universal strategy to fabricate TMDSC nanopatterns via a topotactic conversion method using prepatterned metals as precursors. Typically, robust NbSe2 meandering nanowires can be controllably manufactured on a wafer scale, by which a superconducting nanowire circuit is principally demonstrated toward potential single photon detection. Moreover, versatile superconducting nanocircuits, e.g., periodical circle/triangle hole arrays and spiral nanowires, can be prepared with selected TMD materials (NbS2, TiSe2, or MoTe2). This work provides a generic approach for fabricating nondestructive TMDSC nanocircuits with precise control, which paves the way for the application of TMDSCs in future electronics.
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Affiliation(s)
- Xiaohan Wang
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Hao Wang
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China.
- Hefei National Laboratory, Hefei, 230088, China.
| | - Liang Ma
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Labao Zhang
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China.
- Hefei National Laboratory, Hefei, 230088, China.
| | - Zhuolin Yang
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Daxing Dong
- Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Xi Chen
- Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Haochen Li
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Yanqiu Guan
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Biao Zhang
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Qi Chen
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Lili Shi
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Hui Li
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Zhi Qin
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Xuecou Tu
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Lijian Zhang
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Xiaoqing Jia
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
- Hefei National Laboratory, Hefei, 230088, China
| | - Jian Chen
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
| | - Lin Kang
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China
- Hefei National Laboratory, Hefei, 230088, China
| | - Peiheng Wu
- Research Institute of Superconductor Electronics, School of Electronic Science and Engineering, College of Engineering and Applied Science, Nanjing University, Nanjing, 210023, China.
- Hefei National Laboratory, Hefei, 230088, China.
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8
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Jiang G, Barlas Y. Pair Density Waves from Local Band Geometry. PHYSICAL REVIEW LETTERS 2023; 131:016002. [PMID: 37478459 DOI: 10.1103/physrevlett.131.016002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/27/2023] [Accepted: 05/18/2023] [Indexed: 07/23/2023]
Abstract
A band-projection formalism is developed for calculating the superfluid weight in two-dimensional multiorbital superconductors with an orbital-dependent pairing. It is discovered that, in this case, the band geometric superfluid stiffness tensor can be locally nonpositive definite in some regions of the Brillouin zone. When these regions are large enough or include nodal singularities, the total superfluid weight becomes nonpositive definite due to pairing fluctuations, resulting in the transition of a BCS state to a pair density wave (PDW). This geometric BCS-PDW transition is studied in the context of two-orbital superconductors, and proof of the existence of a geometric BCS-PDW transition in a generic topological flat band is established.
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Affiliation(s)
- Guodong Jiang
- Department of Physics, University of Nevada, Reno, Reno, Nevada 89502, USA
| | - Yafis Barlas
- Department of Physics, University of Nevada, Reno, Reno, Nevada 89502, USA
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9
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Chen H, Gao HJ. Widespread pair density waves spark superconductor search. Nature 2023; 618:910-912. [PMID: 37380686 DOI: 10.1038/d41586-023-01996-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
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10
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Gu Q, Carroll JP, Wang S, Ran S, Broyles C, Siddiquee H, Butch NP, Saha SR, Paglione J, Davis JCS, Liu X. Detection of a pair density wave state in UTe 2. Nature 2023; 618:921-927. [PMID: 37380691 DOI: 10.1038/s41586-023-05919-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/03/2023] [Indexed: 06/30/2023]
Abstract
Spin-triplet topological superconductors should exhibit many unprecedented electronic properties, including fractionalized electronic states relevant to quantum information processing. Although UTe2 may embody such bulk topological superconductivity1-11, its superconductive order parameter Δ(k) remains unknown12. Many diverse forms for Δ(k) are physically possible12 in such heavy fermion materials13. Moreover, intertwined14,15 density waves of spin (SDW), charge (CDW) and pair (PDW) may interpose, with the latter exhibiting spatially modulating14,15 superconductive order parameter Δ(r), electron-pair density16-19 and pairing energy gap17,20-23. Hence, the newly discovered CDW state24 in UTe2 motivates the prospect that a PDW state may exist in this material24,25. To search for it, we visualize the pairing energy gap with μeV-scale energy resolution using superconductive scanning tunnelling microscopy (STM) tips26-31. We detect three PDWs, each with peak-to-peak gap modulations of around 10 μeV and at incommensurate wavevectors Pi=1,2,3 that are indistinguishable from the wavevectors Qi=1,2,3 of the prevenient24 CDW. Concurrent visualization of the UTe2 superconductive PDWs and the non-superconductive CDWs shows that every Pi:Qi pair exhibits a relative spatial phase δϕ ≈ π. From these observations, and given UTe2 as a spin-triplet superconductor12, this PDW state should be a spin-triplet PDW24,25. Although such states do exist32 in superfluid 3He, for superconductors, they are unprecedented.
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Affiliation(s)
- Qiangqiang Gu
- LASSP, Department of Physics, Cornell University, Ithaca, NY, USA
| | - Joseph P Carroll
- LASSP, Department of Physics, Cornell University, Ithaca, NY, USA
- Department of Physics, University College Cork, Cork, Ireland
| | - Shuqiu Wang
- LASSP, Department of Physics, Cornell University, Ithaca, NY, USA.
- Clarendon Laboratory, University of Oxford, Oxford, UK.
| | - Sheng Ran
- Department of Physics, Washington University in St. Louis, St. Louis, MO, USA
| | - Christopher Broyles
- Department of Physics, Washington University in St. Louis, St. Louis, MO, USA
| | - Hasan Siddiquee
- Department of Physics, Washington University in St. Louis, St. Louis, MO, USA
| | - Nicholas P Butch
- Maryland Quantum Materials Center, University of Maryland, College Park, MD, USA
- NIST Center for Neutron Research, Gaithersburg, MD, USA
| | - Shanta R Saha
- Maryland Quantum Materials Center, University of Maryland, College Park, MD, USA
| | - Johnpierre Paglione
- Maryland Quantum Materials Center, University of Maryland, College Park, MD, USA
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | - J C Séamus Davis
- LASSP, Department of Physics, Cornell University, Ithaca, NY, USA.
- Department of Physics, University College Cork, Cork, Ireland.
- Clarendon Laboratory, University of Oxford, Oxford, UK.
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
| | - Xiaolong Liu
- LASSP, Department of Physics, Cornell University, Ithaca, NY, USA.
- Department of Physics and Astronomy, University of Notre Dame, Notre Dame, IN, USA.
- Stavropoulos Center for Complex Quantum Matter, University of Notre Dame, Notre Dame, IN, USA.
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11
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Zhao H, Blackwell R, Thinel M, Handa T, Ishida S, Zhu X, Iyo A, Eisaki H, Pasupathy AN, Fujita K. Smectic pair-density-wave order in EuRbFe 4As 4. Nature 2023; 618:940-945. [PMID: 37380689 DOI: 10.1038/s41586-023-06103-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 04/20/2023] [Indexed: 06/30/2023]
Abstract
The pair density wave (PDW) is a superconducting state in which Cooper pairs carry centre-of-mass momentum in equilibrium, leading to the breaking of translational symmetry1-4. Experimental evidence for such a state exists in high magnetic field5-8 and in some materials that feature density-wave orders that explicitly break translational symmetry9-13. However, evidence for a zero-field PDW state that exists independent of other spatially ordered states has so far been elusive. Here we show that such a state exists in the iron pnictide superconductor EuRbFe4As4, a material that features co-existing superconductivity (superconducting transition temperature (Tc) ≈ 37 kelvin) and magnetism (magnetic transition temperature (Tm) ≈ 15 kelvin)14,15. Using spectroscopic imaging scanning tunnelling microscopy (SI-STM) measurements, we show that the superconducting gap at low temperature has long-range, unidirectional spatial modulations with an incommensurate period of about eight unit cells. Upon increasing the temperature above Tm, the modulated superconductor disappears, but a uniform superconducting gap survives to Tc. When an external magnetic field is applied, gap modulations disappear inside the vortex halo. The SI-STM and bulk measurements show the absence of other density-wave orders, indicating that the PDW state is a primary, zero-field superconducting state in this compound. Both four-fold rotational symmetry and translation symmetry are recovered above Tm, indicating that the PDW is a smectic order.
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Affiliation(s)
- He Zhao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Raymond Blackwell
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Morgan Thinel
- Department of Physics, Columbia University, New York, NY, USA
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Taketo Handa
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Shigeyuki Ishida
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Xiaoyang Zhu
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Akira Iyo
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Hiroshi Eisaki
- Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Abhay N Pasupathy
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA.
- Department of Physics, Columbia University, New York, NY, USA.
| | - Kazuhiro Fujita
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA.
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12
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Liu Y, Wei T, He G, Zhang Y, Wang Z, Wang J. Pair density wave state in a monolayer high-T c iron-based superconductor. Nature 2023; 618:934-939. [PMID: 37380693 DOI: 10.1038/s41586-023-06072-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 04/11/2023] [Indexed: 06/30/2023]
Abstract
The pair density wave (PDW) is an extraordinary superconducting state in which Cooper pairs carry non-zero momentum1,2. Evidence for the existence of intrinsic PDW order in high-temperature (high-Tc) cuprate superconductors3,4 and kagome superconductors5 has emerged recently. However, the PDW order in iron-based high-Tc superconductors has not been observed experimentally. Here, using scanning tunnelling microscopy and spectroscopy, we report the discovery of the PDW state in monolayer iron-based high-Tc Fe(Te,Se) films grown on SrTiO3(001) substrates. The PDW state with a period of λ ≈ 3.6aFe (aFe is the distance between neighbouring Fe atoms) is observed at the domain walls by the spatial electronic modulations of the local density of states, the superconducting gap and the π-phase shift boundaries of the PDW around the vortices of the intertwined charge density wave order. The discovery of the PDW state in the monolayer Fe(Te,Se) film provides a low-dimensional platform to study the interplay between the correlated electronic states and unconventional Cooper pairing in high-Tc superconductors.
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Affiliation(s)
- Yanzhao Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Tianheng Wei
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Guanyang He
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Yi Zhang
- Department of Physics, Shanghai University, Shanghai, China
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, China.
- Hefei National Laboratory, Hefei, China.
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China.
- Beijing Academy of Quantum Information Sciences, Beijing, China.
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13
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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] [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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14
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van Wezel J. A magnetic field for each electron. NATURE MATERIALS 2023; 22:410-411. [PMID: 37002497 DOI: 10.1038/s41563-023-01503-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
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15
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Knapp J, Levitin LV, Nyéki J, Ho AF, Cowan B, Saunders J, Brando M, Geibel C, Kliemt K, Krellner C. Electronuclear Transition into a Spatially Modulated Magnetic State in YbRh_{2}Si_{2}. PHYSICAL REVIEW LETTERS 2023; 130:126802. [PMID: 37027856 DOI: 10.1103/physrevlett.130.126802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 02/03/2023] [Indexed: 06/19/2023]
Abstract
The nature of the antiferromagnetic order in the heavy fermion metal YbRh_{2}Si_{2}, its quantum criticality, and superconductivity, which appears at low mK temperatures, remain open questions. We report measurements of the heat capacity over the wide temperature range 180 μK-80 mK, using current sensing noise thermometry. In zero magnetic field we observe a remarkably sharp heat capacity anomaly at 1.5 mK, which we identify as an electronuclear transition into a state with spatially modulated electronic magnetic order of maximum amplitude 0.1 μ_{B}. We also report results of measurements in magnetic fields in the range 0 to 70 mT, applied perpendicular to the c axis, which show eventual suppression of this order. These results demonstrate a coexistence of a large moment antiferromagnet with putative superconductivity.
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Affiliation(s)
- J Knapp
- Department of Physics, Royal Holloway University of London, TW20 0EX, Egham, United Kingdom
| | - L V Levitin
- Department of Physics, Royal Holloway University of London, TW20 0EX, Egham, United Kingdom
| | - J Nyéki
- Department of Physics, Royal Holloway University of London, TW20 0EX, Egham, United Kingdom
| | - A F Ho
- Department of Physics, Royal Holloway University of London, TW20 0EX, Egham, United Kingdom
| | - B Cowan
- Department of Physics, Royal Holloway University of London, TW20 0EX, Egham, United Kingdom
| | - J Saunders
- Department of Physics, Royal Holloway University of London, TW20 0EX, Egham, United Kingdom
| | - M Brando
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - C Geibel
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - K Kliemt
- Physikalisches Institut, Max-von-Laue-Straße 1, 60438 Frankfurt am Main, Germany
| | - C Krellner
- Physikalisches Institut, Max-von-Laue-Straße 1, 60438 Frankfurt am Main, Germany
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16
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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] [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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17
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On the electron pairing mechanism of copper-oxide high temperature superconductivity. Proc Natl Acad Sci U S A 2022; 119:e2207449119. [PMID: 36067325 PMCID: PMC9477408 DOI: 10.1073/pnas.2207449119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The elementary CuO2 plane sustaining cuprate high-temperature superconductivity occurs typically at the base of a periodic array of edge-sharing CuO5 pyramids. Virtual transitions of electrons between adjacent planar Cu and O atoms, occurring at a rate t/ℏ and across the charge-transfer energy gap [Formula: see text], generate "superexchange" spin-spin interactions of energy [Formula: see text] in an antiferromagnetic correlated-insulator state. However, hole doping this CuO2 plane converts this into a very-high-temperature superconducting state whose electron pairing is exceptional. A leading proposal for the mechanism of this intense electron pairing is that, while hole doping destroys magnetic order, it preserves pair-forming superexchange interactions governed by the charge-transfer energy scale [Formula: see text]. To explore this hypothesis directly at atomic scale, we combine single-electron and electron-pair (Josephson) scanning tunneling microscopy to visualize the interplay of [Formula: see text] and the electron-pair density nP in Bi2Sr2CaCu2O8+x. The responses of both [Formula: see text] and nP to alterations in the distance δ between planar Cu and apical O atoms are then determined. These data reveal the empirical crux of strongly correlated superconductivity in CuO2, the response of the electron-pair condensate to varying the charge-transfer energy. Concurrence of predictions from strong-correlation theory for hole-doped charge-transfer insulators with these observations indicates that charge-transfer superexchange is the electron-pairing mechanism of superconductive Bi2Sr2CaCu2O8+x.
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18
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Abstract
Electron-pair density wave (PDW) states are now an intense focus of research in the field of cuprate correlated superconductivity. PDWs exhibit periodically modulating superconductive electron pairing that can be visualized directly using scanned Josephson tunneling microscopy (SJTM). Although from theory, intertwining the d-wave superconducting (DSC) and PDW order parameters allows a plethora of global electron-pair orders to appear, which one actually occurs in the various cuprates is unknown. Here, we use SJTM to visualize the interplay of PDW and DSC states in Bi2Sr2CaCu2O8+x at a carrier density where the charge density wave modulations are virtually nonexistent. Simultaneous visualization of their amplitudes reveals that the intertwined PDW and DSC are mutually attractive states. Then, by separately imaging the electron-pair density modulations of the two orthogonal PDWs, we discover a robust nematic PDW state. Its spatial arrangement entails Ising domains of opposite nematicity, each consisting primarily of unidirectional and lattice commensurate electron-pair density modulations. Further, we demonstrate by direct imaging that the scattering resonances identifying Zn impurity atom sites occur predominantly within boundaries between these domains. This implies that the nematic PDW state is pinned by Zn atoms, as was recently proposed [Lozano et al., Phys. Rev. B 103, L020502 (2021)]. Taken in combination, these data indicate that the PDW in Bi2Sr2CaCu2O8+x is a vestigial nematic pair density wave state [Agterberg et al. Phys. Rev. B 91, 054502 (2015); Wardh and Granath arXiv:2203.08250].
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19
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Quantum spins and hybridization in artificially-constructed chains of magnetic adatoms on a superconductor. Nat Commun 2022; 13:2160. [PMID: 35443753 PMCID: PMC9021194 DOI: 10.1038/s41467-022-29879-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/01/2022] [Indexed: 11/09/2022] Open
Abstract
Magnetic adatom chains on surfaces constitute fascinating quantum spin systems. Superconducting substrates suppress interactions with bulk electronic excitations but couple the adatom spins to a chain of subgap Yu-Shiba-Rusinov (YSR) quasiparticles. Using a scanning tunneling microscope, we investigate such correlated spin-fermion systems by constructing Fe chains adatom by adatom on superconducting NbSe2. The adatoms couple entirely via the substrate, retaining their quantum spin nature. In dimers, we observe that the deepest YSR state undergoes a quantum phase transition due to Ruderman-Kittel-Kasuya-Yosida interactions, a distinct signature of quantum spins. Chains exhibit coherent hybridization and band formation of the YSR excitations, indicating ferromagnetic coupling. Longer chains develop separate domains due to coexisting charge-density-wave order of NbSe2. Despite the spin-orbit-coupled substrate, we find no signatures of Majoranas, possibly because quantum spins reduce the parameter range for topological superconductivity. We suggest that adatom chains are versatile systems for investigating correlated-electron physics and its interplay with topological superconductivity. Previous studies of magnetic adatom chains on superconducting substrates have mostly focused on the regime of dense chains and classical spins. Here, using scanning tunnelling microscopy, the authors study the excitation spectra of Fe chains on a NbSe2 surface, adatom by adatom, in the regime of quantum spins.
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20
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Huang Z, Song X, Chen Y, Yang H, Yuan P, Ma H, Qiao J, Zhang Y, Sun J, Zhang T, Huang Y, Liu L, Gao HJ, Wang Y. Size Dependence of Charge-Density-Wave Orders in Single-Layer NbSe 2 Hetero/Homophase Junctions. J Phys Chem Lett 2022; 13:1901-1907. [PMID: 35179388 DOI: 10.1021/acs.jpclett.1c04138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Controlling charge-density-wave (CDW) orders in two-dimensional (2D) crystals has attracted a great deal of interest because of their fundamental physics and their demand inse in miniaturized devices. In this work, we systematically studied the size-dependent CDW orders in single-layer hetero/homo-NbSe2 stacking junctions. We found that the CDW orders in the top 1T-NbSe2 layer of the junctions are highly dependent on its lateral size. For the 1T/2H-NbSe2 heterojunction, the critical lateral size of 1T-NbSe2 islands for the formation of well-defined CDW orders is ∼26 nm, whereas below 15 nm, the CDW orders melt. However, for the 1T/1T-NbSe2 homojunction, the CDW orders in the islands can persist even with a lateral size of <11 nm. Our findings illuminate the fresh phenomenon of size-dependent CDW orders existing in 2D van der Waals hetero/homojunctions and provide useful information for the control of CDW orders.
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Affiliation(s)
- Zeping Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Xuan Song
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Yaoyao Chen
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Han Yang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Peiwen Yuan
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Hang Ma
- School of Automation, Beijing Information Science and Technology University, Beijing 100085, China
| | - Jingsi Qiao
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
- Centre for Advanced 2D Materials, National University of Singapore, 117546 Singapore
| | - Yu Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Jiatao Sun
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Teng Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Yuan Huang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Liwei Liu
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yeliang Wang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, Beijing 100081, China
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21
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Chen H, Yang H, Hu B, Zhao Z, Yuan J, Xing Y, Qian G, Huang Z, Li G, Ye Y, Ma S, Ni S, Zhang H, Yin Q, Gong C, Tu Z, Lei H, Tan H, Zhou S, Shen C, Dong X, Yan B, Wang Z, Gao HJ. Roton pair density wave in a strong-coupling kagome superconductor. Nature 2021; 599:222-228. [PMID: 34587621 DOI: 10.1038/s41586-021-03983-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 09/01/2021] [Indexed: 02/08/2023]
Abstract
The transition metal kagome lattice materials host frustrated, correlated and topological quantum states of matter1-9. Recently, a new family of vanadium-based kagome metals, AV3Sb5 (A = K, Rb or Cs), with topological band structures has been discovered10,11. These layered compounds are nonmagnetic and undergo charge density wave transitions before developing superconductivity at low temperatures11-19. Here we report the observation of unconventional superconductivity and a pair density wave (PDW) in CsV3Sb5 using scanning tunnelling microscope/spectroscopy and Josephson scanning tunnelling spectroscopy. We find that CsV3Sb5 exhibits a V-shaped pairing gap Δ ~ 0.5 meV and is a strong-coupling superconductor (2Δ/kBTc ~ 5) that coexists with 4a0 unidirectional and 2a0 × 2a0 charge order. Remarkably, we discover a 3Q PDW accompanied by bidirectional 4a0/3 spatial modulations of the superconducting gap, coherence peak and gap depth in the tunnelling conductance. We term this novel quantum state a roton PDW associated with an underlying vortex-antivortex lattice that can account for the observed conductance modulations. Probing the electronic states in the vortex halo in an applied magnetic field, in strong field that suppresses superconductivity and in zero field above Tc, reveals that the PDW is a primary state responsible for an emergent pseudogap and intertwined electronic order. Our findings show striking analogies and distinctions to the phenomenology of high-Tc cuprate superconductors, and provide groundwork for understanding the microscopic origin of correlated electronic states and superconductivity in vanadium-based kagome metals.
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Affiliation(s)
- Hui Chen
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,Songshan Lake Materials Laboratory, Dongguan, People's Republic of China
| | - Haitao Yang
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,Songshan Lake Materials Laboratory, Dongguan, People's Republic of China
| | - Bin Hu
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Zhen Zhao
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Jie Yuan
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yuqing Xing
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Guojian Qian
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Zihao Huang
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Geng Li
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yuhan Ye
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Sheng Ma
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Shunli Ni
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Hua Zhang
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Qiangwei Yin
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, People's Republic of China
| | - Chunsheng Gong
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, People's Republic of China
| | - Zhijun Tu
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, People's Republic of China
| | - Hechang Lei
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, People's Republic of China
| | - Hengxin Tan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Sen Zhou
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Chengmin Shen
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Xiaoli Dong
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Binghai Yan
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Ziqiang Wang
- Department of Physics, Boston College, Chestnut Hill, MA, USA.
| | - Hong-Jun Gao
- Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, People's Republic of China. .,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, People's Republic of China. .,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, People's Republic of China. .,Songshan Lake Materials Laboratory, Dongguan, People's Republic of China.
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22
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Liu X, Chong YX, Sharma R, Davis JCS. Atomic-scale visualization of electronic fluid flow. NATURE MATERIALS 2021; 20:1480-1484. [PMID: 34462570 DOI: 10.1038/s41563-021-01077-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
The most essential characteristic of any fluid is the velocity field, and this is particularly true for macroscopic quantum fluids1. Although rapid advances2-7 have occurred in quantum fluid velocity field imaging8, the velocity field of a charged superfluid-a superconductor-has never been visualized. Here we use superconducting-tip scanning tunnelling microscopy9-11 to image the electron-pair density and velocity fields of the flowing electron-pair fluid in superconducting NbSe2. Imaging of the velocity fields surrounding a quantized vortex12,13 finds electronic fluid flow with speeds reaching 10,000 km h-1. Together with independent imaging of the electron-pair density via Josephson tunnelling, we visualize the supercurrent density, which peaks above 3 × 107 A cm-2. The spatial patterns in electronic fluid flow and magneto-hydrodynamics reveal hexagonal structures coaligned to the crystal lattice and quasiparticle bound states14, as long anticipated15-18. These techniques pave the way for electronic fluid flow visualization studies of other charged quantum fluids.
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Affiliation(s)
- Xiaolong Liu
- Department of Physics, Cornell University, Ithaca, NY, USA
| | - Yi Xue Chong
- Department of Physics, Cornell University, Ithaca, NY, USA
| | - Rahul Sharma
- Department of Physics, Cornell University, Ithaca, NY, USA
- Department of Physics, University of Maryland, College Park, MD, USA
| | - J C Séamus Davis
- Department of Physics, Cornell University, Ithaca, NY, USA.
- Department of Physics, University College Cork, Cork, Ireland.
- Max-Planck Institute for Chemical Physics of Solids, Dresden, Germany.
- Clarendon Laboratory, University of Oxford, Oxford, UK.
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23
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Wang S, Choubey P, Chong YX, Chen W, Ren W, Eisaki H, Uchida S, Hirschfeld PJ, Davis JCS. Scattering interference signature of a pair density wave state in the cuprate pseudogap phase. Nat Commun 2021; 12:6087. [PMID: 34667154 PMCID: PMC8526682 DOI: 10.1038/s41467-021-26028-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 09/09/2021] [Indexed: 11/21/2022] Open
Abstract
An unidentified quantum fluid designated the pseudogap (PG) phase is produced by electron-density depletion in the CuO2 antiferromagnetic insulator. Current theories suggest that the PG phase may be a pair density wave (PDW) state characterized by a spatially modulating density of electron pairs. Such a state should exhibit a periodically modulating energy gap [Formula: see text] in real-space, and a characteristic quasiparticle scattering interference (QPI) signature [Formula: see text] in wavevector space. By studying strongly underdoped Bi2Sr2CaDyCu2O8 at hole-density ~0.08 in the superconductive phase, we detect the 8a0-periodic [Formula: see text] modulations signifying a PDW coexisting with superconductivity. Then, by visualizing the temperature dependence of this electronic structure from the superconducting into the pseudogap phase, we find the evolution of the scattering interference signature [Formula: see text] that is predicted specifically for the temperature dependence of an 8a0-periodic PDW. These observations are consistent with theory for the transition from a PDW state coexisting with d-wave superconductivity to a pure PDW state in the Bi2Sr2CaDyCu2O8 pseudogap phase.
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Affiliation(s)
- Shuqiu Wang
- Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Peayush Choubey
- Institut für Theoretische Physik III, Ruhr-Universität Bochum, Bochum, Germany
- Department of Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, India
| | - Yi Xue Chong
- LASSP, Department of Physics, Cornell University, Ithaca, NY, USA
| | - Weijiong Chen
- Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Wangping Ren
- Clarendon Laboratory, University of Oxford, Oxford, UK
| | - H Eisaki
- Institute of Advanced Industrial Science and Tech., Tsukuba, Ibaraki, Japan
| | - S Uchida
- Institute of Advanced Industrial Science and Tech., Tsukuba, Ibaraki, Japan
| | | | - J C Séamus Davis
- Clarendon Laboratory, University of Oxford, Oxford, UK.
- LASSP, Department of Physics, Cornell University, Ithaca, NY, USA.
- Department of Physics, University College Cork, Cork, Ireland.
- Max-Planck Institute for Chemical Physics of Solids, Dresden, Germany.
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24
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Fernández-Lomana M, Wu B, Martín-Vega F, Sánchez-Barquilla R, Álvarez-Montoya R, Castilla JM, Navarrete J, Marijuan JR, Herrera E, Suderow H, Guillamón I. Millikelvin scanning tunneling microscope at 20/22 T with a graphite enabled stick-slip approach and an energy resolution below 8 μeV: Application to conductance quantization at 20 T in single atom point contacts of Al and Au and to the charge density wave of 2H-NbSe 2. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:093701. [PMID: 34598511 DOI: 10.1063/5.0059394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/21/2021] [Indexed: 06/13/2023]
Abstract
We describe a scanning tunneling microscope (STM) that operates at magnetic fields up to 22 T and temperatures down to 80 mK. We discuss the design of the STM head, with an improved coarse approach, the vibration isolation system, and efforts to improve the energy resolution using compact filters for multiple lines. We measure the superconducting gap and Josephson effect in aluminum and show that we can resolve features in the density of states as small as 8 μeV. We measure the quantization of conductance in atomic size contacts and make atomic resolution and density of states images in the layered material 2H-NbSe2. The latter experiments are performed by continuously operating the STM at magnetic fields of 20 T in periods of several days without interruption.
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Affiliation(s)
- Marta Fernández-Lomana
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Beilun Wu
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Francisco Martín-Vega
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Raquel Sánchez-Barquilla
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Rafael Álvarez-Montoya
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - José María Castilla
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - José Navarrete
- SEGAINVEX, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | | | - Edwin Herrera
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Hermann Suderow
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Isabel Guillamón
- Laboratorio de Bajas Temperaturas y Altos Campos Magnéticos, Unidad Asociada (UAM/CSIC), Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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25
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Liu X, Chong YX, Sharma R, Davis JCS. Discovery of a Cooper-pair density wave state in a transition-metal dichalcogenide. Science 2021. [DOI: 10.1126/science.abd4607] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Imaging an exotic state
Among the most intriguing of the many phases of cuprate superconductors is the so-called pair density wave (PDW) state. PDW is characterized by a spatially modulated density of Cooper pairs and can be detected with a scanning tunneling microscope equipped with a superconducting tip. Liu
et al.
used Josephson tunneling microscopy, modified for the task, to detect PDW in niobium diselenide, a superconductor with a layered hexagonal structure. The PDW state is expected to appear in other transition metal dichalcogenides as well.
Science
, abd4607, this issue p.
1447
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Affiliation(s)
- Xiaolong Liu
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14850, USA
| | - Yi Xue Chong
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14850, USA
| | - Rahul Sharma
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14850, USA
- Department of Physics, University of Maryland, College Park, MD 20740, USA
| | - J. C. Séamus Davis
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14850, USA
- Department of Physics, University College Cork, Cork T12 R5C, Ireland
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
- Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, UK
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