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Kim H, Kim JK, Kwon J, Kim J, Kim HWJ, Ha S, Kim K, Lee W, Kim J, Cho GY, Heo H, Jang J, Sahle CJ, Longo A, Strempfer J, Fabbris G, Choi Y, Haskel D, Kim J, Kim JW, Kim BJ. Quantum spin nematic phase in a square-lattice iridate. Nature 2024; 625:264-269. [PMID: 38093009 DOI: 10.1038/s41586-023-06829-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 11/03/2023] [Indexed: 01/12/2024]
Abstract
Spin nematic is a magnetic analogue of classical liquid crystals, a fourth state of matter exhibiting characteristics of both liquid and solid1,2. Particularly intriguing is a valence-bond spin nematic3-5, in which spins are quantum entangled to form a multipolar order without breaking time-reversal symmetry, but its unambiguous experimental realization remains elusive. Here we establish a spin nematic phase in the square-lattice iridate Sr2IrO4, which approximately realizes a pseudospin one-half Heisenberg antiferromagnet in the strong spin-orbit coupling limit6-9. Upon cooling, the transition into the spin nematic phase at TC ≈ 263 K is marked by a divergence in the static spin quadrupole susceptibility extracted from our Raman spectra and concomitant emergence of a collective mode associated with the spontaneous breaking of rotational symmetries. The quadrupolar order persists in the antiferromagnetic phase below TN ≈ 230 K and becomes directly observable through its interference with the antiferromagnetic order in resonant X-ray diffraction, which allows us to uniquely determine its spatial structure. Further, we find using resonant inelastic X-ray scattering a complete breakdown of coherent magnon excitations at short-wavelength scales, suggesting a many-body quantum entanglement in the antiferromagnetic state10,11. Taken together, our results reveal a quantum order underlying the Néel antiferromagnet that is widely believed to be intimately connected to the mechanism of high-temperature superconductivity12,13.
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Affiliation(s)
- Hoon Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Jin-Kwang Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Junyoung Kwon
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Jimin Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Hyun-Woo J Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Seunghyeok Ha
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Kwangrae Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Wonjun Lee
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Jonghwan Kim
- Center for Van der Waals Quantum Solids, Institute for Basic Science, Pohang, Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, Korea
| | - Gil Young Cho
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea
| | - Hyeokjun Heo
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
| | - Joonho Jang
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
| | - C J Sahle
- ESRF, The European Synchrotron, Grenoble, France
| | - A Longo
- ESRF, The European Synchrotron, Grenoble, France
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR, UOS Palermo, Palermo, Italy
| | - J Strempfer
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - Y Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - Jungho Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - J -W Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - B J Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, Pohang, South Korea.
- Department of Physics, Pohang University of Science and Technology, Pohang, South Korea.
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2
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Miao H, Zhang TT, Li HX, Fabbris G, Said AH, Tartaglia R, Yilmaz T, Vescovo E, Yin JX, Murakami S, Feng XL, Jiang K, Wu XL, Wang AF, Okamoto S, Wang YL, Lee HN. Signature of spin-phonon coupling driven charge density wave in a kagome magnet. Nat Commun 2023; 14:6183. [PMID: 37793998 PMCID: PMC10550957 DOI: 10.1038/s41467-023-41957-5] [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: 04/12/2023] [Accepted: 09/21/2023] [Indexed: 10/06/2023] Open
Abstract
The intertwining between spin, charge, and lattice degrees of freedom can give rise to unusual macroscopic quantum states, including high-temperature superconductivity and quantum anomalous Hall effects. Recently, a charge density wave (CDW) has been observed in the kagome antiferromagnet FeGe, indicative of possible intertwining physics. An outstanding question is that whether magnetic correlation is fundamental for the spontaneous spatial symmetry breaking orders. Here, utilizing elastic and high-resolution inelastic x-ray scattering, we observe a c-axis superlattice vector that coexists with the 2[Formula: see text]2[Formula: see text]1 CDW vectors in the kagome plane. Most interestingly, between the magnetic and CDW transition temperatures, the phonon dynamical structure factor shows a giant phonon-energy hardening and a substantial phonon linewidth broadening near the c-axis wavevectors, both signaling the spin-phonon coupling. By first principles and model calculations, we show that both the static spin polarization and dynamic spin excitations intertwine with the phonon to drive the spatial symmetry breaking in FeGe.
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Affiliation(s)
- H Miao
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| | - T T Zhang
- Department of Physics, Tokyo Institute of Technology, Okayama, Meguro-ku, Tokyo, Japan
| | - H X Li
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Advanced Materials Thrust, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou, China
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - A H Said
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - R Tartaglia
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
- "Gleb Wataghin" Institute of Physics, University of Campinas, Campinas, São Paulo, Brazil
| | - T Yilmaz
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA
| | - E Vescovo
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA
| | - J-X Yin
- Laboratory for Quantum Emergence, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - S Murakami
- Department of Physics, Tokyo Institute of Technology, Okayama, Meguro-ku, Tokyo, Japan
| | - X L Feng
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - K Jiang
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - X L Wu
- Low Temperature Physics Laboratory, College of Physics and Center of Quantum Materials and Devices, Chongqing University, Chongqing, China
| | - A F Wang
- Low Temperature Physics Laboratory, College of Physics and Center of Quantum Materials and Devices, Chongqing University, Chongqing, China.
| | - S Okamoto
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| | - Y L Wang
- School of Emerging Technology, University of Science and Technology of China, Hefei, Anhui, China.
| | - H N Lee
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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3
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de la Torre A, Zager B, Bahrami F, Upton MH, Kim J, Fabbris G, Lee GH, Yang W, Haskel D, Tafti F, Plumb KW. Momentum-independent magnetic excitation continuum in the honeycomb iridate H 3LiIr 2O 6. Nat Commun 2023; 14:5018. [PMID: 37596328 PMCID: PMC10439105 DOI: 10.1038/s41467-023-40769-x] [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: 02/08/2023] [Accepted: 08/07/2023] [Indexed: 08/20/2023] Open
Abstract
Understanding the interplay between the inherent disorder and the correlated fluctuating-spin ground state is a key element in the search for quantum spin liquids. H3LiIr2O6 is considered to be a spin liquid that is proximate to the Kitaev-limit quantum spin liquid. Its ground state shows no magnetic order or spin freezing as expected for the spin liquid state. However, hydrogen zero-point motion and stacking faults are known to be present. The resulting bond disorder has been invoked to explain the existence of unexpected low-energy spin excitations, although data interpretation remains challenging. Here, we use resonant X-ray spectroscopies to map the collective excitations in H3LiIr2O6 and characterize its magnetic state. In the low-temperature correlated state, we reveal a broad bandwidth of magnetic excitations. The central energy and the high-energy tail of the continuum are consistent with expectations for dominant ferromagnetic Kitaev interactions between dynamically fluctuating spins. Furthermore, the absence of a momentum dependence to these excitations are consistent with disorder-induced broken translational invariance. Our low-energy data and the energy and width of the crystal field excitations support an interpretation of H3LiIr2O6 as a disordered topological spin liquid in close proximity to bond-disordered versions of the Kitaev quantum spin liquid.
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Affiliation(s)
- A de la Torre
- Department of Physics, Brown University, Providence, RI, 02912, USA.
| | - B Zager
- Department of Physics, Brown University, Providence, RI, 02912, USA
| | - F Bahrami
- Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA
| | - M H Upton
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - J Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - G-H Lee
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, 94720, USA
| | - W Yang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, 94720, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - F Tafti
- Department of Physics, Boston College, Chestnut Hill, MA, 02467, USA
| | - K W Plumb
- Department of Physics, Brown University, Providence, RI, 02912, USA.
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4
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Fabbris G, Meyers D, Shen Y, Bisogni V, Zhang J, Mitchell JF, Norman MR, Johnston S, Feng J, Chiuzbăian GS, Nicolaou A, Jaouen N, Dean MPM. Resonant inelastic x-ray scattering data for Ruddlesden-Popper and reduced Ruddlesden-Popper nickelates. Sci Data 2023; 10:174. [PMID: 36991033 PMCID: PMC10060392 DOI: 10.1038/s41597-023-02079-1] [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: 02/13/2023] [Accepted: 03/16/2023] [Indexed: 03/31/2023] Open
Abstract
Ruddlesden-Popper and reduced Ruddlesden-Popper nickelates are intriguing candidates for mimicking the properties of high-temperature superconducting cuprates. The degree of similarity between these nickelates and cuprates has been the subject of considerable debate. Resonant inelastic x-ray scattering (RIXS) has played an important role in exploring their electronic and magnetic excitations, but these efforts have been stymied by inconsistencies between different samples and the lack of publicly available data for detailed comparison. To address this issue, we present open RIXS data on La4Ni3O10 and La4Ni3O8.
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Affiliation(s)
- G Fabbris
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA.
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois, 60439, USA.
| | - D Meyers
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
- Department of Physics, Oklahoma State University, Stillwater, Oklahoma, 74078, USA
| | - Y Shen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - V Bisogni
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - J Zhang
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois, 60439, USA
- Institute of Crystal Materials, Shandong University, Jinan, Shandong, 250100, China
| | - J F Mitchell
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois, 60439, USA
| | - M R Norman
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois, 60439, USA
| | - S Johnston
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee, 37966, USA
- Institute of Advanced Materials and Manufacturing, The University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - J Feng
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, 75005, Paris, France
- Institute of Advanced Science Facilities, Shenzhen, Guangdong, 518107, China
| | - G S Chiuzbăian
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, 75005, Paris, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192, Gif-sur-Yvette, France
| | - A Nicolaou
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192, Gif-sur-Yvette, France
| | - N Jaouen
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192, Gif-sur-Yvette, France
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA.
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5
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Shen Y, Sears J, Fabbris G, Weichselbaum A, Yin W, Zhao H, Mazzone DG, Miao H, Upton MH, Casa D, Acevedo-Esteves R, Nelson C, Barbour AM, Mazzoli C, Cao G, Dean MPM. Emergence of Spinons in Layered Trimer Iridate Ba_{4}Ir_{3}O_{10}. Phys Rev Lett 2022; 129:207201. [PMID: 36461990 DOI: 10.1103/physrevlett.129.207201] [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: 01/04/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
Spinons are well known as the elementary excitations of one-dimensional antiferromagnetic chains, but means to realize spinons in higher dimensions is the subject of intense research. Here, we use resonant x-ray scattering to study the layered trimer iridate Ba_{4}Ir_{3}O_{10}, which shows no magnetic order down to 0.2 K. An emergent one-dimensional spinon continuum is observed that can be well described by XXZ spin-1/2 chains with a magnetic exchange of ∼55 meV and a small Ising-like anisotropy. With 2% isovalent Sr doping, magnetic order appears below T_{N}=130 K along with sharper excitations in (Ba_{1-x}Sr_{x})_{4}Ir_{3}O_{10}. Combining our data with exact diagonalization calculations, we find that the frustrated intratrimer interactions effectively reduce the system into decoupled spin chains, the subtle balance of which can be easily tipped by perturbations such as chemical doping. Our results put Ba_{4}Ir_{3}O_{10} between the one-dimensional chain and two-dimensional quantum spin liquid scenarios, illustrating a new way to suppress magnetic order and realize fractional spinons.
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Affiliation(s)
- Y Shen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J Sears
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Weichselbaum
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - W Yin
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - H Zhao
- Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - D G Mazzone
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - H Miao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - M H Upton
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Casa
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - R Acevedo-Esteves
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - C Nelson
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - A M Barbour
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - C Mazzoli
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - G Cao
- Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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6
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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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7
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Arias-Egido E, Laguna-Marco MA, Piquer C, Jiménez-Cavero P, Lucas I, Morellón L, Gallego F, Rivera-Calzada A, Cabero-Piris M, Santamaria J, Fabbris G, Haskel D, Boada R, Díaz-Moreno S. Dimensionality-driven metal-insulator transition in spin-orbit-coupled IrO 2. Nanoscale 2021; 13:17125-17135. [PMID: 34635906 DOI: 10.1039/d1nr04207f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A metal-insulator transition is observed in spin-orbit-coupled IrO2 thin films upon reduction of the film thickness. In the epitaxially grown samples, the critical thickness (t ∼ 1.5-2.2 nm) is found to depend on growth orientation (001), (100) or (110). Interestingly from the applied point of view, the insulating behavior is found even in polycrystalline ultrathin films. By analyzing the experimental electrical response with various theoretical models, we find good fits to the Efros-Shklovskii-VRH and the Arrhenius-type behaviors, which suggests an important role of electron correlations in determining the electrical properties of IrO2. Our magnetic measurements also point to a significant role of magnetic order. Altogether, our results would point to a mixed Slater- and Mott-type of insulator.
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Affiliation(s)
- E Arias-Egido
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC - Universidad de Zaragoza, Zaragoza 50009, Spain.
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
| | - M A Laguna-Marco
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC - Universidad de Zaragoza, Zaragoza 50009, Spain.
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
| | - C Piquer
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC - Universidad de Zaragoza, Zaragoza 50009, Spain.
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
| | - P Jiménez-Cavero
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC - Universidad de Zaragoza, Zaragoza 50009, Spain.
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
| | - I Lucas
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC - Universidad de Zaragoza, Zaragoza 50009, Spain.
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
| | - L Morellón
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC - Universidad de Zaragoza, Zaragoza 50009, Spain.
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
| | - F Gallego
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | - M Cabero-Piris
- ICTS - Centro Nacional de Microscopía Electrónica, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - J Santamaria
- GFMC, Universidad Complutense de Madrid, 28040 Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, 28049 Madrid, Spain
- GFMC, Instituto de Magnetismo Aplicado, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - R Boada
- Department of Chemistry Universitat Autonoma de Barcelona 08193 Bellaterra, Barcelona, Spain
- Diamond Light Source Ltd Harwell Science and Innovation Campus Didcot, Oxfordshire OX11 0DE, UK
| | - S Díaz-Moreno
- Diamond Light Source Ltd Harwell Science and Innovation Campus Didcot, Oxfordshire OX11 0DE, UK
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8
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Li H, Zhang TT, Said A, Fabbris G, Mazzone DG, Yan JQ, Mandrus D, Halász GB, Okamoto S, Murakami S, Dean MPM, Lee HN, Miao H. Giant phonon anomalies in the proximate Kitaev quantum spin liquid α-RuCl 3. Nat Commun 2021; 12:3513. [PMID: 34112804 PMCID: PMC8192767 DOI: 10.1038/s41467-021-23826-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 04/05/2021] [Accepted: 04/30/2021] [Indexed: 11/18/2022] Open
Abstract
The Kitaev quantum spin liquid epitomizes an entangled topological state, for which two flavors of fractionalized low-energy excitations are predicted: the itinerant Majorana fermion and the Z2 gauge flux. It was proposed recently that fingerprints of fractional excitations are encoded in the phonon spectra of Kitaev quantum spin liquids through a novel fractional-excitation-phonon coupling. Here, we detect anomalous phonon effects in α-RuCl3 using inelastic X-ray scattering with meV resolution. At high temperature, we discover interlaced optical phonons intercepting a transverse acoustic phonon between 3 and 7 meV. Upon decreasing temperature, the optical phonons display a large intensity enhancement near the Kitaev energy, JK~8 meV, that coincides with a giant acoustic phonon softening near the Z2 gauge flux energy scale. These phonon anomalies signify the coupling of phonon and Kitaev magnetic excitations in α-RuCl3 and demonstrates a proof-of-principle method to detect anomalous excitations in topological quantum materials.
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Affiliation(s)
- Haoxiang Li
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - T T Zhang
- Department of Physics, Tokyo Institute of Technology, Okayama, Meguro-ku, Tokyo, Japan
- Tokodai Institute for Element Strategy, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama, Kanagawa, Japan
| | - A Said
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - D G Mazzone
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, Villigen, Switzerland
| | - J Q Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - D Mandrus
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Department of Materials Science and Engineering, the University of Tennessee at Knoxville, Knoxville, TN, USA
| | - Gábor B Halász
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - S Okamoto
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - S Murakami
- Department of Physics, Tokyo Institute of Technology, Okayama, Meguro-ku, Tokyo, Japan
- Tokodai Institute for Element Strategy, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama, Kanagawa, Japan
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, USA
| | - H N Lee
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - H Miao
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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9
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Shen Y, Fabbris G, Miao H, Cao Y, Meyers D, Mazzone DG, Assefa TA, Chen XM, Kisslinger K, Prabhakaran D, Boothroyd AT, Tranquada JM, Hu W, Barbour AM, Wilkins SB, Mazzoli C, Robinson IK, Dean MPM. Charge Condensation and Lattice Coupling Drives Stripe Formation in Nickelates. Phys Rev Lett 2021; 126:177601. [PMID: 33988428 DOI: 10.1103/physrevlett.126.177601] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Revealing the predominant driving force behind symmetry breaking in correlated materials is sometimes a formidable task due to the intertwined nature of different degrees of freedom. This is the case for La_{2-x}Sr_{x}NiO_{4+δ}, in which coupled incommensurate charge and spin stripes form at low temperatures. Here, we use resonant x-ray photon correlation spectroscopy to study the temporal stability and domain memory of the charge and spin stripes in La_{2-x}Sr_{x}NiO_{4+δ}. Although spin stripes are more spatially correlated, charge stripes maintain a better temporal stability against temperature change. More intriguingly, charge order shows robust domain memory with thermal cycling up to 250 K, far above the ordering temperature. These results demonstrate the pinning of charge stripes to the lattice and that charge condensation is the predominant factor in the formation of stripe orders in nickelates.
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Affiliation(s)
- Y Shen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - G Fabbris
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - H Miao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Y Cao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - D Meyers
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078, USA
| | - D G Mazzone
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - T A Assefa
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - X M Chen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - K Kisslinger
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - D Prabhakaran
- Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU, United Kingdom
| | - A T Boothroyd
- Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU, United Kingdom
| | - J M Tranquada
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - W Hu
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - A M Barbour
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - S B Wilkins
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - C Mazzoli
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - I K Robinson
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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10
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Lin JQ, Villar Arribi P, Fabbris G, Botana AS, Meyers D, Miao H, Shen Y, Mazzone DG, Feng J, Chiuzbăian SG, Nag A, Walters AC, García-Fernández M, Zhou KJ, Pelliciari J, Jarrige I, Freeland JW, Zhang J, Mitchell JF, Bisogni V, Liu X, Norman MR, Dean MPM. Strong Superexchange in a d^{9-δ} Nickelate Revealed by Resonant Inelastic X-Ray Scattering. Phys Rev Lett 2021; 126:087001. [PMID: 33709756 DOI: 10.1103/physrevlett.126.087001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 01/15/2021] [Indexed: 06/12/2023]
Abstract
The discovery of superconductivity in a d^{9-δ} nickelate has inspired disparate theoretical perspectives regarding the essential physics of this class of materials. A key issue is the magnitude of the magnetic superexchange, which relates to whether cuprate-like high-temperature nickelate superconductivity could be realized. We address this question using Ni L-edge and O K-edge spectroscopy of the reduced d^{9-1/3} trilayer nickelates R_{4}Ni_{3}O_{8} (where R=La, Pr) and associated theoretical modeling. A magnon energy scale of ∼80 meV resulting from a nearest-neighbor magnetic exchange of J=69(4) meV is observed, proving that d^{9-δ} nickelates can host a large superexchange. This value, along with that of the Ni-O hybridization estimated from our O K-edge data, implies that trilayer nickelates represent an intermediate case between the infinite-layer nickelates and the cuprates. Layered nickelates thus provide a route to testing the relevance of superexchange to nickelate superconductivity.
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Affiliation(s)
- J Q Lin
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - P Villar Arribi
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - G Fabbris
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - A S Botana
- Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
| | - D Meyers
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078, USA
| | - H Miao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Y Shen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - D G Mazzone
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - J Feng
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, UMR 7614, 4 place Jussieu, 75252 Paris Cedex 05, France
| | - S G Chiuzbăian
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, UMR 7614, 4 place Jussieu, 75252 Paris Cedex 05, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - A Nag
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - A C Walters
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - M García-Fernández
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Ke-Jin Zhou
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - J Pelliciari
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - I Jarrige
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J W Freeland
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Junjie Zhang
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
- Institute of Crystal Materials, Shandong University, Jinan, Shandong 250100, China
| | - J F Mitchell
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - V Bisogni
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - X Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - M R Norman
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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11
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Thomas SM, Santos FB, Christensen MH, Asaba T, Ronning F, Thompson JD, Bauer ED, Fernandes RM, Fabbris G, Rosa PFS. Evidence for a pressure-induced antiferromagnetic quantum critical point in intermediate-valence UTe 2. Sci Adv 2020; 6:eabc8709. [PMID: 33055167 PMCID: PMC7556831 DOI: 10.1126/sciadv.abc8709] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/27/2020] [Indexed: 06/01/2023]
Abstract
UTe2 is a recently discovered unconventional superconductor that has attracted much interest because of its potentially spin-triplet topological superconductivity. Our ac calorimetry, electrical resistivity, and x-ray absorption study of UTe2 under applied pressure reveals key insights on the superconducting and magnetic states surrounding pressure-induced quantum criticality at P c1 = 1.3 GPa. First, our specific heat data at low pressures, combined with a phenomenological model, show that pressure alters the balance between two closely competing superconducting orders. Second, near 1.5 GPa, we detect two bulk transitions that trigger changes in the resistivity, which are consistent with antiferromagnetic order, rather than ferromagnetism. Third, the emergence of magnetism is accompanied by an increase in valence toward a U4+ (5f 2) state, which indicates that UTe2 exhibits intermediate valence at ambient pressure. Our results suggest that antiferromagnetic fluctuations may play a more substantial role on the superconducting state of UTe2 than previously thought.
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Affiliation(s)
- S M Thomas
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
| | - F B Santos
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
- Escola de Engenharia de Lorena, Universidade de Sao Paulo (EEL-USP), Materials Engineering Department (Demar), Lorena, Sao Paolo, Brazil
| | - M H Christensen
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA
| | - T Asaba
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - F Ronning
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - J D Thompson
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - E D Bauer
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - R M Fernandes
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - P F S Rosa
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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12
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Haskel D, Fabbris G, Kim JH, Veiga LSI, Mardegan JRL, Escanhoela CA, Chikara S, Struzhkin V, Senthil T, Kim BJ, Cao G, Kim JW. Possible Quantum Paramagnetism in Compressed Sr_{2}IrO_{4}. Phys Rev Lett 2020; 124:067201. [PMID: 32109088 DOI: 10.1103/physrevlett.124.067201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/13/2020] [Indexed: 06/10/2023]
Abstract
The effect of compression on the magnetic ground state of Sr_{2}IrO_{4} is studied with x-ray resonant techniques in the diamond anvil cell. The weak interlayer exchange coupling between square-planar 2D IrO_{2} layers is readily modified upon compression, with a crossover between magnetic structures around 7 GPa mimicking the effect of an applied magnetic field at ambient pressure. Higher pressures drive an order-disorder magnetic phase transition with no magnetic order detected above 17-20 GPa. The persistence of strong exchange interactions between J_{eff}=1/2 magnetic moments within the insulating IrO_{2} layers up to at least 35 GPa points to a highly frustrated magnetic state in compressed Sr_{2}IrO_{4}, opening the door for realization of novel quantum paramagnetic phases driven by extended 5d orbitals with entangled spin and orbital degrees of freedom.
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Affiliation(s)
- D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J H Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - L S I Veiga
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Brazilian Synchrotron Light Laboratory (LNLS), Campinas, São Paulo 13083-970, Brazil
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo 13083-859, Brazil
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - J R L Mardegan
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, São Paulo 13083-859, Brazil
| | - C A Escanhoela
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Brazilian Synchrotron Light Laboratory (LNLS), Campinas, São Paulo 13083-970, Brazil
| | - S Chikara
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - V Struzhkin
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
| | - T Senthil
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - B J Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), 77 Cheongam-Ro, Pohang 790-784, South Korea
- Department of Physics, Pohang University of Science and Technology, Pohang 790-784, South Korea
| | - G Cao
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - J-W Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
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13
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Zhang TT, Miao H, Wang Q, Lin JQ, Cao Y, Fabbris G, Said AH, Liu X, Lei HC, Fang Z, Weng HM, Dean MPM. Phononic Helical Nodal Lines with PT Protection in MoB_{2}. Phys Rev Lett 2019; 123:245302. [PMID: 31922848 DOI: 10.1103/physrevlett.123.245302] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Indexed: 06/10/2023]
Abstract
While condensed matter systems host both fermionic and bosonic quasiparticles, reliably predicting and empirically verifying topological states is only mature for Fermionic electronic structures, leaving topological Bosonic excitations sporadically explored. This is unfortunate, as Bosonic systems such as phonons offer the opportunity to assess spinless band structures where nodal lines can be realized without invoking special additional symetries to protect against spin-orbit coupling. Here we combine first-principles calculations and meV-resolution inelastic x-ray scattering to demonstrate the first realization of parity-time reversal symmetry protected helical nodal lines in the phonon spectrum of MoB_{2}. This structure is unique to phononic systems as the spin-orbit coupling present in electronic systems tends to lift the degeneracy away from high-symmetry locations. Our study establishes a protocol to accurately identify topological Bosonic excitations, opening a new route to explore exotic topological states in crystalline materials.
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Affiliation(s)
- T T Zhang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Department of Physics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551, Japan
- Tokodai Institute for Element Strategy, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - H Miao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Q Wang
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-devices, Renmin University of China, Beijing, China
| | - J Q Lin
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Y Cao
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A H Said
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - X Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - H C Lei
- Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-devices, Renmin University of China, Beijing, China
| | - Z Fang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - H M Weng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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14
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Chen XM, Mazzoli C, Cao Y, Thampy V, Barbour AM, Hu W, Lu M, Assefa TA, Miao H, Fabbris G, Gu GD, Tranquada JM, Dean MPM, Wilkins SB, Robinson IK. Charge density wave memory in a cuprate superconductor. Nat Commun 2019; 10:1435. [PMID: 30926816 PMCID: PMC6440992 DOI: 10.1038/s41467-019-09433-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 03/11/2019] [Indexed: 11/09/2022] Open
Abstract
Although CDW correlations are a ubiquitous feature of the superconducting cuprates, their disparate properties suggest a crucial role for pinning the CDW to the lattice. Here, we report coherent resonant X-ray speckle correlation analysis, which directly determines the reproducibility of CDW domain patterns in La1.875Ba0.125CuO4 (LBCO 1/8) with thermal cycling. While CDW order is only observed below 54 K, where a structural phase transition creates inequivalent Cu-O bonds, we discover remarkably reproducible CDW domain memory upon repeated cycling to far higher temperatures. That memory is only lost on cycling to 240(3) K, which recovers the four-fold symmetry of the CuO2 planes. We infer that the structural features that develop below 240 K determine the CDW pinning landscape below 54 K. This opens a view into the complex coupling between charge and lattice degrees of freedom in superconducting cuprates.
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Affiliation(s)
- X M Chen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA. .,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - C Mazzoli
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Y Cao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - V Thampy
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.,Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - A M Barbour
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - W Hu
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - M Lu
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - T A Assefa
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - H Miao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - G Fabbris
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - G D Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - J M Tranquada
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA.
| | - S B Wilkins
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA.
| | - I K Robinson
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY, 11973, USA. .,London Centre for Nanotechnology, University College, Gower St., London, WC1E 6BT, UK.
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15
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Meyers D, Cao Y, Fabbris G, Robinson NJ, Hao L, Frederick C, Traynor N, Yang J, Lin J, Upton MH, Casa D, Kim JW, Gog T, Karapetrova E, Choi Y, Haskel D, Ryan PJ, Horak L, Liu X, Liu J, Dean MPM. Magnetism in iridate heterostructures leveraged by structural distortions. Sci Rep 2019; 9:4263. [PMID: 30862782 PMCID: PMC6414659 DOI: 10.1038/s41598-019-39422-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/18/2019] [Indexed: 11/09/2022] Open
Abstract
Fundamental control of magnetic coupling through heterostructure morphology is a prerequisite for rational engineering of magnetic ground states. We report the tuning of magnetic interactions in superlattices composed of single and bilayers of SrIrO3 inter-spaced with SrTiO3 in analogy to the Ruddlesden-Popper series iridates. Magnetic scattering shows predominately c-axis antiferromagnetic orientation of the magnetic moments for the bilayer, as in Sr3Ir2O7. However, the magnetic excitation gap, measured by resonant inelastic x-ray scattering, is quite different between the two structures, evidencing a significant change in the stability of the competing magnetic phases. In contrast, the single layer iridate hosts a more bulk-like gap. We find these changes are driven by bending of the c-axis Ir-O-Ir bond, which is much weaker in the single layer, and subsequent local environment changes, evidenced through x-ray diffraction and magnetic excitation modeling. Our findings demonstrate how large changes in the magnetic interactions can be tailored and probed in spin-orbit coupled heterostructures by engineering subtle structural modulations.
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Affiliation(s)
- D Meyers
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA.
| | - Yue Cao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - G Fabbris
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Neil J Robinson
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Lin Hao
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - C Frederick
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - N Traynor
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - J Yang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Jiaqi Lin
- 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
| | - M H Upton
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA
| | - D Casa
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA
| | - Jong-Woo Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA
| | - T Gog
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA
| | - E Karapetrova
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA
| | - Yongseong Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA
| | - P J Ryan
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois, 60439, USA.,School of Physical Sciences, Dublin City University, Dublin 9, Ireland
| | - Lukas Horak
- Department of Condensed Matter Physics, Charles University, Ke Karlovu 3, Prague, 12116, Czech Republic
| | - X Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.,Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Jian Liu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, 37996, USA.
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA.
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16
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Meyers D, Nakatsukasa K, Mu S, Hao L, Yang J, Cao Y, Fabbris G, Miao H, Pelliciari J, McNally D, Dantz M, Paris E, Karapetrova E, Choi Y, Haskel D, Shafer P, Arenholz E, Schmitt T, Berlijn T, Johnston S, Liu J, Dean MPM. Decoupling Carrier Concentration and Electron-Phonon Coupling in Oxide Heterostructures Observed with Resonant Inelastic X-Ray Scattering. Phys Rev Lett 2018; 121:236802. [PMID: 30576191 DOI: 10.1103/physrevlett.121.236802] [Citation(s) in RCA: 3] [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: 06/20/2018] [Revised: 10/15/2018] [Indexed: 06/09/2023]
Abstract
We report the observation of multiple phonon satellite features in ultrathin superlattices of the form nSrIrO_{3}/mSrTiO_{3} using resonant inelastic x-ray scattering (RIXS). As the values of n and m vary, the energy loss spectra show a systematic evolution in the relative intensity of the phonon satellites. Using a closed-form solution for the RIXS cross section, we extract the variation in the electron-phonon coupling strength as a function of n and m. Combined with the negligible carrier doping into the SrTiO_{3} layers, these results indicate that the tuning of the electron-phonon coupling can be effectively decoupled from doping. This work both showcases a feasible method to extract the electron-phonon coupling in superlattices and unveils a potential route for tuning this coupling, which is often associated with superconductivity in SrTiO_{3}-based systems.
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Affiliation(s)
- D Meyers
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Ken Nakatsukasa
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Sai Mu
- Department of Condensed Matter Physics and Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Lin Hao
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Junyi Yang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Yue Cao
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Hu Miao
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J Pelliciari
- Photon Science Division, Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - D McNally
- Photon Science Division, Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Dantz
- Photon Science Division, Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - E Paris
- Photon Science Division, Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - E Karapetrova
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Yongseong Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - E Arenholz
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Thorsten Schmitt
- Photon Science Division, Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Tom Berlijn
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Computational Science and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S Johnston
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Joint Institute of Advanced Materials at The University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Jian Liu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M P M Dean
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
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17
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Song J, Fabbris G, Bi W, Haskel D, Schilling JS. Pressure-Induced Superconductivity in Elemental Ytterbium Metal. Phys Rev Lett 2018; 121:037004. [PMID: 30085803 DOI: 10.1103/physrevlett.121.037004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/30/2018] [Indexed: 06/08/2023]
Abstract
Ytterbium (Yb) metal is divalent and nonmagnetic (4f^{14} configuration). Under pressure its valence increases significantly leading to the expectation that magnetic instabilities and other highly correlated electron effects may appear before a stable trivalent state is reached (4f^{13} configuration). We carried out electrical resistivity and ac magnetic susceptibility measurements to 179 GPa over the temperature range 1.4-295 K. No evidence for magnetic order is observed. However, Yb becomes a superconductor at 86 GPa with T_{c}≃1.4 K, increasing to 4.6 K at 179 GPa. X-ray absorption spectroscopy shows that Yb remains mixed valent to at least 125 GPa, pointing to an active role of f electrons in the emergence of superconductivity in this simple, elemental solid.
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Affiliation(s)
- J Song
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - W Bi
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J S Schilling
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
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18
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Fabbris G, Meyers D, Xu L, Katukuri VM, Hozoi L, Liu X, Chen ZY, Okamoto J, Schmitt T, Uldry A, Delley B, Gu GD, Prabhakaran D, Boothroyd AT, van den Brink J, Huang DJ, Dean MPM. Doping Dependence of Collective Spin and Orbital Excitations in the Spin-1 Quantum Antiferromagnet La_{2-x}Sr_{x}NiO_{4} Observed by X Rays. Phys Rev Lett 2017; 118:156402. [PMID: 28452512 DOI: 10.1103/physrevlett.118.156402] [Citation(s) in RCA: 7] [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: 12/14/2016] [Indexed: 05/23/2023]
Abstract
We report the first empirical demonstration that resonant inelastic x-ray scattering (RIXS) is sensitive to collective magnetic excitations in S=1 systems by probing the Ni L_{3} edge of La_{2-x}Sr_{x}NiO_{4} (x=0, 0.33, 0.45). The magnetic excitation peak is asymmetric, indicating the presence of single and multi-spin-flip excitations. As the hole doping level is increased, the zone boundary magnon energy is suppressed at a much larger rate than that in hole doped cuprates. Based on the analysis of the orbital and charge excitations observed by RIXS, we argue that this difference is related to the orbital character of the doped holes in these two families. This work establishes RIXS as a probe of fundamental magnetic interactions in nickelates opening the way towards studies of heterostructures and ultrafast pump-probe experiments.
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Affiliation(s)
- G Fabbris
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - D Meyers
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - L Xu
- Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstraße, 20, 01069 Dresden, Germany
| | - V M Katukuri
- Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstraße, 20, 01069 Dresden, Germany
| | - L Hozoi
- Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstraße, 20, 01069 Dresden, Germany
| | - X Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Z-Y Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - J Okamoto
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - T Schmitt
- Research Department "Synchotron Radiation and Nanotechnology", Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - A Uldry
- Condensed Matter Theory Group, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - B Delley
- Condensed Matter Theory Group, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - G D Gu
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - D Prabhakaran
- Department of Physics, University of Oxford, Clarendon Laboratory, Oxford, OX1 3PU, United Kingdom
| | - A T Boothroyd
- Department of Physics, University of Oxford, Clarendon Laboratory, Oxford, OX1 3PU, United Kingdom
| | - J van den Brink
- Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstraße, 20, 01069 Dresden, Germany
| | - D J Huang
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - M P M Dean
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
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19
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Fabbris G, Meyers D, Okamoto J, Pelliciari J, Disa AS, Huang Y, Chen ZY, Wu WB, Chen CT, Ismail-Beigi S, Ahn CH, Walker FJ, Huang DJ, Schmitt T, Dean MPM. Orbital Engineering in Nickelate Heterostructures Driven by Anisotropic Oxygen Hybridization rather than Orbital Energy Levels. Phys Rev Lett 2016; 117:147401. [PMID: 27740843 DOI: 10.1103/physrevlett.117.147401] [Citation(s) in RCA: 4] [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: 03/17/2016] [Indexed: 06/06/2023]
Abstract
Resonant inelastic x-ray scattering is used to investigate the electronic origin of orbital polarization in nickelate heterostructures taking LaTiO_{3}-LaNiO_{3}-3×(LaAlO_{3}), a system with exceptionally large polarization, as a model system. We find that heterostructuring generates only minor changes in the Ni 3d orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O K-edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This provides an explanation for the limited success of theoretical predictions based on tuning orbital energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.
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Affiliation(s)
- G Fabbris
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - D Meyers
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J Okamoto
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - J Pelliciari
- Research Department "Synchrotron Radiation and Nanotechnology", Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - A S Disa
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Y Huang
- Research Department "Synchrotron Radiation and Nanotechnology", Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Z-Y Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - W B Wu
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - C T Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - S Ismail-Beigi
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA
| | - C H Ahn
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA
| | - F J Walker
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - D J Huang
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - T Schmitt
- Research Department "Synchrotron Radiation and Nanotechnology", Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M P M Dean
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
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Takayama T, Kato A, Dinnebier R, Nuss J, Kono H, Veiga LSI, Fabbris G, Haskel D, Takagi H. Hyperhoneycomb Iridate β-Li2IrO3 as a platform for Kitaev magnetism. Phys Rev Lett 2015; 114:077202. [PMID: 25763972 DOI: 10.1103/physrevlett.114.077202] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Indexed: 06/04/2023]
Abstract
A complex iridium oxide β-Li(2)IrO(3) crystallizes in a hyperhoneycomb structure, a three-dimensional analogue of honeycomb lattice, and is found to be a spin-orbital Mott insulator with J(eff)=1/2 moment. Ir ions are connected to the three neighboring Ir ions via Ir-O(2)-Ir bonding planes, which very likely gives rise to bond-dependent ferromagnetic interactions between the J(eff)=1/2 moments, an essential ingredient of Kitaev model with a spin liquid ground state. Dominant ferromagnetic interaction between J(eff)=1/2 moments is indeed confirmed by the temperature dependence of magnetic susceptibility χ(T) which shows a positive Curie-Weiss temperature θ(CW)∼+40 K. A magnetic ordering with a very small entropy change, likely associated with a noncollinear arrangement of J(eff)=1/2 moments, is observed at T(c)=38 K. With the application of magnetic field to the ordered state, a large moment of more than 0.35 μ(B)/Ir is induced above 3 T, a substantially polarized J(eff)=1/2 state. We argue that the close proximity to ferromagnetism and the presence of large fluctuations evidence that the ground state of hyperhoneycomb β-Li(2)IrO(3) is located in close proximity of a Kitaev spin liquid.
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Affiliation(s)
- T Takayama
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
- Department of Physics and Department of Advanced Materials, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
| | - A Kato
- Department of Physics and Department of Advanced Materials, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
| | - R Dinnebier
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - J Nuss
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - H Kono
- Department of Physics and Department of Advanced Materials, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
| | - L S I Veiga
- Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas, Campinas, São Paulo 13083-859, Brazil
- Laboratório Nacional de Luz Síncrotron, Campinas, São Paulo 13083-970, Brazil
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - H Takagi
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
- Department of Physics and Department of Advanced Materials, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
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21
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Haskel D, Fabbris G, Zhernenkov M, Kong PP, Jin CQ, Cao G, van Veenendaal M. Pressure tuning of the spin-orbit coupled ground state in Sr2IrO4. Phys Rev Lett 2012; 109:027204. [PMID: 23030204 DOI: 10.1103/physrevlett.109.027204] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Indexed: 06/01/2023]
Abstract
X-ray absorption spectroscopy studies of the magnetic-insulating ground state of Sr2IrO4 at ambient pressure show a clear deviation from a strong spin-orbit (SO) limit J(eff)=1/2 state, a result of local exchange interactions and a nonzero tetragonal crystal field mixing SO split J(eff)=1/2, 3/2 states. X-ray magnetic circular dichroism measurements in a diamond anvil cell show a magnetic transition at a pressure of ∼17 GPa, where the "weak" ferromagnetic moment is quenched despite transport measurements showing insulating behavior to at least 40 GPa. The magnetic transition has implications for the origin of the insulating gap and the nature of exchange interactions in this SO coupled system. The expectation value of the angular part of the SO interaction, <L·S>, extrapolates to zero at ∼80-90 GPa where an increased bandwidth strongly mixes J(eff)=1/2, 3/2 states and SO interactions no longer dominate the electronic ground state of Sr2IrO4.
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Affiliation(s)
- D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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