1
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Ryee S, Witt N, Wehling TO. Quenched Pair Breaking by Interlayer Correlations as a Key to Superconductivity in La_{3}Ni_{2}O_{7}. PHYSICAL REVIEW LETTERS 2024; 133:096002. [PMID: 39270168 DOI: 10.1103/physrevlett.133.096002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 06/05/2024] [Accepted: 07/29/2024] [Indexed: 09/15/2024]
Abstract
The recent discovery of superconductivity in La_{3}Ni_{2}O_{7} with T_{c}≃80 K under high pressure opens up a new route to high-T_{c} superconductivity. This material realizes a bilayer square lattice model featuring a strong interlayer hybridization unlike many unconventional superconductors. A key question in this regard concerns how electronic correlations driven by the interlayer hybridization affect the low-energy electronic structure and the concomitant superconductivity. Here, we demonstrate using a cluster dynamical mean-field theory that the interlayer electronic correlations (IECs) induce a Lifshitz transition resulting in a change of Fermi surface topology. By solving an appropriate gap equation, we further show that the leading pairing instability, s± wave, is enhanced by the IECs. The underlying mechanism is the quenching of a strong ferromagnetic channel, resulting from the Lifshitz transition driven by the IECs. Based on this picture, we provide a possible reason of why superconductivity emerges only under high pressure.
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2
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Yang XP, Yao YT, Zheng P, Guan S, Zhou H, Cochran TA, Lin CM, Yin JX, Zhou X, Cheng ZJ, Li Z, Shi T, Hossain MS, Chi S, Belopolski I, Jiang YX, Litskevich M, Xu G, Tian Z, Bansil A, Yin Z, Jia S, Chang TR, Hasan MZ. A topological Hund nodal line antiferromagnet. Nat Commun 2024; 15:7052. [PMID: 39147740 PMCID: PMC11327286 DOI: 10.1038/s41467-024-51255-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 08/02/2024] [Indexed: 08/17/2024] Open
Abstract
The interplay of topology, magnetism, and correlations gives rise to intriguing phases of matter. In this study, through state-of-the-art angle-resolved photoemission spectroscopy, density functional theory, and dynamical mean-field theory calculations, we visualize a fourfold degenerate Dirac nodal line at the boundary of the bulk Brillouin zone in the antiferromagnet YMn2Ge2. We further demonstrate that this gapless, antiferromagnetic Dirac nodal line is enforced by the combination of magnetism, space-time inversion symmetry, and nonsymmorphic lattice symmetry. The corresponding drumhead surface states traverse the whole surface Brillouin zone. YMn2Ge2 thus serves as a platform to exhibit the interplay of multiple degenerate nodal physics and antiferromagnetism. Interestingly, the magnetic nodal line displays a d-orbital dependent renormalization along its trajectory in momentum space, thereby manifesting Hund's coupling. Our findings offer insights into the effect of electronic correlations on magnetic Dirac nodal lines, leading to an antiferromagnetic Hund nodal line.
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Affiliation(s)
- Xian P Yang
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA.
| | - Yueh-Ting Yao
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
| | - Pengyu Zheng
- School of Physics & Astronomy and Center for Advanced Quantum Studies, Beijing Normal University, Beijing, China
| | - Shuyue Guan
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Huibin Zhou
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Tyler A Cochran
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - Che-Min Lin
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
| | - Jia-Xin Yin
- Department of Physics, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Xiaoting Zhou
- Department of Physics, Northeastern University, Boston, MA, USA
- Quantum Materials and Sensing Institute, Northeastern University, Burlington, MA, USA
| | - Zi-Jia Cheng
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - Zhaohu Li
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Tong Shi
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Md Shafayat Hossain
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - Shengwei Chi
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ilya Belopolski
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - Yu-Xiao Jiang
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - Maksim Litskevich
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA
| | - Gang Xu
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Wuhan Institute of Quantum Technology, Wuhan, Hubei, China
| | - Zhaoming Tian
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, MA, USA
- Quantum Materials and Sensing Institute, Northeastern University, Burlington, MA, USA
| | - Zhiping Yin
- School of Physics & Astronomy and Center for Advanced Quantum Studies, Beijing Normal University, Beijing, China
- Key Laboratory of Multiscale Spin Physics (Ministry of Education), Beijing Normal University, Beijing, China
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing, China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, China
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan, Taiwan.
- Center for Quantum Frontiers of Research and Technology (QFort), Tainan, Taiwan.
- Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan.
| | - M Zahid Hasan
- Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA.
- Princeton Institute for Science and Technology of Materials, Princeton University, Princeton, NJ, USA.
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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3
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Samani N, Zhang G, Pavarini E. Map of Crystal-Field Effects in Correlated Layered t_{2g}^{n} Perovskites. PHYSICAL REVIEW LETTERS 2024; 132:236505. [PMID: 38905685 DOI: 10.1103/physrevlett.132.236505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 06/23/2024]
Abstract
Correlated metallic layered t_{2g}^{n} perovskites are intensively studied and yet their low-energy electronic properties remain hotly debated. Important elements of the puzzle, beside the on-site Coulomb repulsion, are the tetragonal crystal-field splitting and the spin-orbit interaction. Here, we show that they control the electronic properties principally via form and occupations of natural orbitals. We discuss consequences for shape and topology of the Fermi surface, effective masses, and metal-insulator transition, building a map of crystal-field effects. The emerging picture captures electronic-structure trends in this family of systems within a single framework.
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Affiliation(s)
| | - Guoren Zhang
- Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
- School of Physics and Technology, Nantong University, Nantong 226019, People's Republic of China
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
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4
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Reinhoffer C, Esser S, Esser S, Mashkovich EA, Germanskiy S, Gegenwart P, Anders F, van Loosdrecht PHM, Wang Z. Strong Terahertz Third-Harmonic Generation by Kinetic Heavy Quasiparticles in CaRuO_{3}. PHYSICAL REVIEW LETTERS 2024; 132:196501. [PMID: 38804953 DOI: 10.1103/physrevlett.132.196501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 04/15/2024] [Indexed: 05/29/2024]
Abstract
We report on time-resolved nonlinear terahertz spectroscopy of a strongly correlated ruthenate, CaRuO_{3}, as a function of temperature, frequency, and terahertz field strength. Third-harmonic radiation for frequencies up to 2.1 THz is observed evidently at low temperatures below 80 K, where the low-frequency linear dynamical response deviates from the Drude model and a coherent heavy quasiparticle band emerges by strong correlations associated with the Hund's coupling. Phenomenologically, by taking an experimentally observed frequency-dependent scattering rate, the deviation of the field driven kinetics from the Drude behavior is reconciled in a time-dependent Boltzmann description, which allows an attribution of the observed third-harmonic generation to the terahertz field driven nonlinear kinetics of the heavy quasiparticles.
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Affiliation(s)
- Chris Reinhoffer
- Institute of Physics II, University of Cologne, 50937 Cologne, Germany
| | - Sven Esser
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | - Sebastian Esser
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | | | - Semyon Germanskiy
- Institute of Physics II, University of Cologne, 50937 Cologne, Germany
| | - Philipp Gegenwart
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, University of Augsburg, 86159 Augsburg, Germany
| | - Frithjof Anders
- Department of Physics, TU Dortmund University, 44227 Dortmund, Germany
| | | | - Zhe Wang
- Institute of Physics II, University of Cologne, 50937 Cologne, Germany
- Department of Physics, TU Dortmund University, 44227 Dortmund, Germany
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5
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Yao Q, Xue Y, Zhao B, Zhu Y, Li Z, Yang Z. Orbital-Selectivity-Induced Robust Quantum Anomalous Hall Effect in Hund's Metals MgFeP. NANO LETTERS 2024; 24:1563-1569. [PMID: 38262051 DOI: 10.1021/acs.nanolett.3c04098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Ferromagnetic (FM) states with high Curie temperatures (Tc) and strong spin-orbit coupling (SOC) are indispensable for the long-sought room-temperature quantum anomalous Hall (QAH) effects. Here, we propose a two-dimensional (2D) iron-based monolayer MgFeP that exhibits a notably high FM Tc (about 1525 K) along with exceptional structural stabilities. The unique multiorbital nature in MgFeP, where localized d x 2 - y 2 and dxz/yz orbitals coexist with itinerant dxy and dz2 orbitals, renders the monolayer a Hund's metal and in an orbital-selective Mott phase (OSMP). This OSMP triggers an FM double exchange mechanism, rationalizing the high Tc in the Hund's metal. This material transitions to a QAH insulator upon consideration of the SOC effect. By leveraging orbital selectivity, the QAH band gap can be enlarged by more than two times (to 137 meV). Our findings showcase Hund's metals as a promising material platform for realizing high-performance quantum topological electronic devices.
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Affiliation(s)
- Qingzhao Yao
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences (MOE) and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Yang Xue
- School of Physics, East China University of Science and Technology, Shanghai 200237, China
| | - Bao Zhao
- School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252059, China
| | - Ye Zhu
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences (MOE) and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Zhijian Li
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences (MOE) and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Zhongqin Yang
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences (MOE) and Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, Shanghai 200030, China
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6
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Hunter A, Beck S, Cappelli E, Margot F, Straub M, Alexanian Y, Gatti G, Watson MD, Kim TK, Cacho C, Plumb NC, Shi M, Radović M, Sokolov DA, Mackenzie AP, Zingl M, Mravlje J, Georges A, Baumberger F, Tamai A. Fate of Quasiparticles at High Temperature in the Correlated Metal Sr_{2}RuO_{4}. PHYSICAL REVIEW LETTERS 2023; 131:236502. [PMID: 38134803 DOI: 10.1103/physrevlett.131.236502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/08/2023] [Indexed: 12/24/2023]
Abstract
We study the temperature evolution of quasiparticles in the correlated metal Sr_{2}RuO_{4}. Our angle resolved photoemission data show that quasiparticles persist up to temperatures above 200 K, far beyond the Fermi liquid regime. Extracting the quasiparticle self-energy, we demonstrate that the quasiparticle residue Z increases with increasing temperature. Quasiparticles eventually disappear on approaching the bad metal state of Sr_{2}RuO_{4} not by losing weight but via excessive broadening from super-Planckian scattering. We further show that the Fermi surface of Sr_{2}RuO_{4}-defined as the loci where the spectral function peaks-deflates with increasing temperature. These findings are in semiquantitative agreement with dynamical mean field theory calculations.
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Affiliation(s)
- A Hunter
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S Beck
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
| | - E Cappelli
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - F Margot
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - M Straub
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Y Alexanian
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - G Gatti
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - M D Watson
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - C Cacho
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Radović
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - D A Sokolov
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - A P Mackenzie
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - M Zingl
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
| | - J Mravlje
- Department of Theoretical Physics, Institute Jozef Stefan, Jamova 39, SI-1001 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana
| | - A Georges
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
- Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France
- Centre de Physique Théorique, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
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7
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Suzuki H, Wang L, Bertinshaw J, Strand HUR, Käser S, Krautloher M, Yang Z, Wentzell N, Parcollet O, Jerzembeck F, Kikugawa N, Mackenzie AP, Georges A, Hansmann P, Gretarsson H, Keimer B. Distinct spin and orbital dynamics in Sr 2RuO 4. Nat Commun 2023; 14:7042. [PMID: 37923750 PMCID: PMC10624926 DOI: 10.1038/s41467-023-42804-3] [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: 03/24/2023] [Accepted: 10/20/2023] [Indexed: 11/06/2023] Open
Abstract
The unconventional superconductor Sr2RuO4 has long served as a benchmark for theories of correlated-electron materials. The determination of the superconducting pairing mechanism requires detailed experimental information on collective bosonic excitations as potential mediators of Cooper pairing. We have used Ru L3-edge resonant inelastic x-ray scattering to obtain comprehensive maps of the electronic excitations of Sr2RuO4 over the entire Brillouin zone. We observe multiple branches of dispersive spin and orbital excitations associated with distinctly different energy scales. The spin and orbital dynamical response functions calculated within the dynamical mean-field theory are in excellent agreement with the experimental data. Our results highlight the Hund metal nature of Sr2RuO4 and provide key information for the understanding of its unconventional superconductivity.
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Affiliation(s)
- H Suzuki
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany.
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, 980-8578, Japan.
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, 980-8578, Japan.
| | - L Wang
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany
| | - J Bertinshaw
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany
| | - H U R Strand
- School of Science and Technology, Örebro University, Fakultetsgatan 1, SE-701 82, Örebro, Sweden
- Institute for Molecules and Materials, Radboud University, 6525 AJ, Nijmegen, the Netherlands
| | - S Käser
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany
- Department of Physics, Friedrich-Alexander-University (FAU) of Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - M Krautloher
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany
| | - Z Yang
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany
| | - N Wentzell
- Center for Computational Quantum Physics, Flatiron Institute, Simons Foundation, 162 5th Avenue, New York, 10010, USA
| | - O Parcollet
- Center for Computational Quantum Physics, Flatiron Institute, Simons Foundation, 162 5th Avenue, New York, 10010, USA
- Université Paris-Saclay, CNRS, CEA, Institut de physique théorique, 91191, Gif-sur-Yvette, France
| | - F Jerzembeck
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - N Kikugawa
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0003, Japan
| | - A P Mackenzie
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - A Georges
- Center for Computational Quantum Physics, Flatiron Institute, Simons Foundation, 162 5th Avenue, New York, 10010, USA
- Collége de France, 11 place Marcelin Berthelot, 75005, Paris, France
- Centre de Physique Théorique (CPHT), CNRS, Ecole Polytechnique, IP Paris, 91128, Palaiseau, France
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva 4, Switzerland
| | - P Hansmann
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany
- Department of Physics, Friedrich-Alexander-University (FAU) of Erlangen-Nürnberg, 91058, Erlangen, Germany
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187, Dresden, Germany
| | - H Gretarsson
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany.
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607, Hamburg, Germany.
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569, Stuttgart, Germany.
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8
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Yang PY, Noad HML, Barber ME, Kikugawa N, Sokolov DA, Mackenzie AP, Hicks CW. Probing Momentum-Dependent Scattering in Uniaxially Stressed Sr_{2}RuO_{4} through the Hall Effect. PHYSICAL REVIEW LETTERS 2023; 131:036301. [PMID: 37540856 DOI: 10.1103/physrevlett.131.036301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 06/22/2023] [Indexed: 08/06/2023]
Abstract
The largest Fermi surface sheet of the correlated metal Sr_{2}RuO_{4} can be driven through a Lifshitz transition between an electronlike and an open geometry by uniaxial stress applied along the [100] lattice direction. Here, we investigate the effect of this transition on the longitudinal resistivity ρ_{xx} and the Hall coefficient R_{H}. ρ_{xx}(T), when Sr_{2}RuO_{4} is tuned to this transition, is found to have a T^{2}logT form, as expected for a Fermi liquid tuned to a Lifshitz transition. R_{H} is found to become more negative as the Fermi surface transitions from an electronlike to an open geometry, opposite to general expectations from this change in topology. The magnitude of the change in R_{H} implies that scattering changes throughout the Brillouin zone, not just at the point in k space where the transition occurs. In a model of orbital-dependent scattering, the electron-electron scattering rate on sections of Fermi surface with xy orbital weight is found to decrease dramatically.
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Affiliation(s)
- Po-Ya Yang
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187 Dresden, Germany
| | - Hilary M L Noad
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187 Dresden, Germany
| | - Mark E Barber
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187 Dresden, Germany
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
- Geballe Laboratory for Advanced Materials, Stanford, California 94305, USA
| | - Naoki Kikugawa
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan
| | - Dmitry A Sokolov
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187 Dresden, Germany
| | - Andrew P Mackenzie
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187 Dresden, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - Clifford W Hicks
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187 Dresden, Germany
- School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, United Kingdom
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9
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Jang BG, He Y, Shim JH, Mao HK, Kim DY. Oxygen-Driven Enhancement of the Electron Correlation in Hexagonal Iron at Earth's Inner Core Conditions. J Phys Chem Lett 2023; 14:3884-3890. [PMID: 37071052 PMCID: PMC10150722 DOI: 10.1021/acs.jpclett.3c00500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/11/2023] [Indexed: 05/03/2023]
Abstract
Earth's inner core (IC) consists of mainly iron with some light elements. Understanding its structure and related physical properties has been elusive as a result of its required extremely high pressure and temperature conditions. The phase of iron, elastic anisotropy, and density-velocity deficit at the IC have long been questions of great interest. Here, we find that the electron correlation effect is enhanced by oxygen and modifies several important features, including the stability of iron oxides. Oxygen atoms energetically stabilize hexagonal-structured iron at IC conditions and induce elastic anisotropy. Electrical resistivity is much enhanced in comparison to pure hexagonal close-packed (hcp) iron as a result of the enhanced electron correlation effect, supporting the conventional thermal convection model. Moreover, our calculated seismic velocity shows a quantitative match with geologically observed preliminary reference Earth model (PREM) data. We suggest that oxygen is the essential light element to understand and model Earth's IC.
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Affiliation(s)
- Bo Gyu Jang
- Center
for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People’s Republic of China
- Korea
Institute for Advanced Study, Seoul 02455, Korea
| | - Yu He
- Center
for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People’s Republic of China
- Key
Laboratory of High-Temperature and High-Pressure Study of the Earth’s
Interior, Institute of Geochemistry, Chinese
Academy of Sciences, Guiyang, Guizhou 550081, People’s Republic of China
| | - Ji Hoon Shim
- Department
of Chemistry, Pohang University of Science
and Technology, Pohang 37673, Korea
- Division
of Advanced Materials Science, Pohang University
of Science and Technology, Pohang 37673, Korea
| | - Ho-kwang Mao
- Center
for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People’s Republic of China
| | - Duck Young Kim
- Center
for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People’s Republic of China
- Shanghai
Key Laboratory of Material Frontiers Research in Extreme Environments
(MFree), Shanghai Advanced Research in Physical
Sciences (SHARPS), Pudong, Shanghai 201203, P.R. China
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10
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Kim JR, Sohn B, Lee HJ, Lee S, Ko EK, Hahn S, Lee S, Kim Y, Kim D, Kim HJ, Kim Y, Son J, Ahn CH, Walker FJ, Go A, Kim M, Kim CH, Kim C, Noh TW. Heteroepitaxial Control of Fermi Liquid, Hund Metal, and Mott Insulator Phases in Single-Atomic-Layer Ruthenates. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208833. [PMID: 36739615 DOI: 10.1002/adma.202208833] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 01/08/2023] [Indexed: 06/18/2023]
Abstract
Interfaces between dissimilar correlated oxides can offer devices with versatile functionalities, and great efforts have been made to manipulate interfacial electronic phases. However, realizing such phases is often hampered by the inability to directly access the electronic structure information; most correlated interfacial phenomena appear within a few atomic layers from the interface. Here, atomic-scale epitaxy and photoemission spectroscopy are utilized to realize the interface control of correlated electronic phases in atomic-scale ruthenate-titanate heterostructures. While bulk SrRuO3 is a ferromagnetic metal, the heterointerfaces exclusively generate three distinct correlated phases in the single-atomic-layer limit. The theoretical analysis reveals that atomic-scale structural proximity effects yield Fermi liquid, Hund metal, and Mott insulator phases in the quantum-confined SrRuO3 . These results highlight the extensive interfacial tunability of electronic phases, hitherto hidden in the atomically thin correlated heterostructure. Moreover, this experimental platform suggests a way to control interfacial electronic phases of various correlated materials.
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Affiliation(s)
- Jeong Rae Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Byungmin Sohn
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Department of Applied Physics, Yale University, New Haven, CT, 06520, USA
| | - Hyeong Jun Lee
- Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS), Daejeon, 34126, South Korea
| | - Sangmin Lee
- Department of Materials Science and Engineering and Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, South Korea
| | - Eun Kyo Ko
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Sungsoo Hahn
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Sangjae Lee
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
| | - Younsik Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Donghan Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Hong Joon Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Youngdo Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Jaeseok Son
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Charles H Ahn
- Department of Applied Physics, Yale University, New Haven, CT, 06520, USA
- Department of Physics, Yale University, New Haven, CT, 06520, USA
| | - Frederick J Walker
- Department of Applied Physics, Yale University, New Haven, CT, 06520, USA
| | - Ara Go
- Department of Physics, Chonnam National University, Gwangju, 61186, South Korea
| | - Miyoung Kim
- Department of Materials Science and Engineering and Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, South Korea
| | - Choong H Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Changyoung Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Tae Won Noh
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul, 08826, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
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11
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Ryee S, Wehling TO. Switching between Mott-Hubbard and Hund Physics in Moiré Quantum Simulators. NANO LETTERS 2023; 23:573-579. [PMID: 36622289 DOI: 10.1021/acs.nanolett.2c04169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Mott-Hubbard and Hund electron correlations have been realized thus far in separate classes of materials. Here, we show that a single moiré homobilayer encompasses both kinds of physics in a controllable manner. We develop a microscopic multiband model that we solve by dynamical mean-field theory to nonperturbatively address the local many-body correlations. We demonstrate how tuning with twist angle, dielectric screening, and hole density allows us to switch between Mott-Hubbard and Hund correlated states in a twisted WSe2 bilayer. The underlying mechanism is based on controlling Coulomb-interaction-driven orbital polarization and the energetics of concomitant local singlet and triplet spin configurations. From a comparison to recent experimental transport data, we find signatures of a filling-controlled transition from a triplet charge-transfer insulator to a Hund-Mott metal. Our finding establishes twisted transition-metal dichalcogenides as a tunable platform for exotic phases of quantum matter emerging from large local spin moments.
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Affiliation(s)
- Siheon Ryee
- I. Institute of Theoretical Physics, University of Hamburg, Notkestrasse 9, 22607Hamburg, Germany
| | - Tim O Wehling
- I. Institute of Theoretical Physics, University of Hamburg, Notkestrasse 9, 22607Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761Hamburg, Germany
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12
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Gendron F, Cliche N, Amadon B. Role of pressure on electronic, magnetic and structural properties at iron's Curie temperature: a DFT + DMFT study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:464003. [PMID: 36067782 DOI: 10.1088/1361-648x/ac8fd0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
We use the combination of density functional theory and dynamical mean-field theory to compute the Curie temperature of the iron body-centered cubicαphase and probe its pressure dependence. Our calculations reveal thatTCshows a decrease which is very weak over a domain of pressures that is much larger than the stability domain of theαphase. This is consistent with the experimental results. We highlight the importance of the Hund's couplingJnot only on the electronic and magnetic properties but also on the structural properties. Lastly, we analyze the electronic and magnetic properties under pressure and discuss the evolution of magnetic moments in both phases in relation to the change of Curie temperature.
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Affiliation(s)
- F Gendron
- CEA, DAM, DIF, F-91297 Arpajon, France
- Université Paris-Saclay, CEA, Laboratoire Matière en Conditions Extrêmes, 91680 Bruyères-le-Châtel, France
| | - N Cliche
- CEA, DAM, DIF, F-91297 Arpajon, France
| | - B Amadon
- CEA, DAM, DIF, F-91297 Arpajon, France
- Université Paris-Saclay, CEA, Laboratoire Matière en Conditions Extrêmes, 91680 Bruyères-le-Châtel, France
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13
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Jerzembeck F, Røising HS, Steppke A, Rosner H, Sokolov DA, Kikugawa N, Scaffidi T, Simon SH, Mackenzie AP, Hicks CW. The superconductivity of Sr 2RuO 4 under c-axis uniaxial stress. Nat Commun 2022; 13:4596. [PMID: 35933412 PMCID: PMC9357014 DOI: 10.1038/s41467-022-32177-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/19/2022] [Indexed: 11/15/2022] Open
Abstract
Applying in-plane uniaxial pressure to strongly correlated low-dimensional systems has been shown to tune the electronic structure dramatically. For example, the unconventional superconductor Sr2RuO4 can be tuned through a single Van Hove point, resulting in strong enhancement of both Tc and Hc2. Out-of-plane (c axis) uniaxial pressure is expected to tune the quasi-two-dimensional structure even more strongly, by pushing it towards two Van Hove points simultaneously. Here, we achieve a record uniaxial stress of 3.2 GPa along the c axis of Sr2RuO4. Hc2 increases, as expected for increasing density of states, but unexpectedly Tc falls. As a first attempt to explain this result, we present three-dimensional calculations in the weak interaction limit. We find that within the weak-coupling framework there is no single order parameter that can account for the contrasting effects of in-plane versus c-axis uniaxial stress, which makes this new result a strong constraint on theories of the superconductivity of Sr2RuO4. In the superconductor Sr2RuO4, in-plane strain is known to enhance both the superconducting transition temperature Tc and upper critical field Hc2, but the effect of out-of-plane strain has not been studied. Here, the authors find that Hc2 is enhanced under out-of-plane strain, but Tc unexpectedly decreases.
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Affiliation(s)
- Fabian Jerzembeck
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187, Dresden, Germany.
| | - Henrik S Røising
- Nordita, KTH Royal Institute of Technology and Stockholm University, Hannes Alfvéns väg 12, SE-106 91, Stockholm, Sweden
| | - Alexander Steppke
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187, Dresden, Germany
| | - Helge Rosner
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187, Dresden, Germany
| | - Dmitry A Sokolov
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187, Dresden, Germany
| | - Naoki Kikugawa
- National Institute for Materials Science, Tsukuba, 305-0003, Japan
| | - Thomas Scaffidi
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada.,Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA
| | - Steven H Simon
- Rudolf Peierls Center for Theoretical Physics, Oxford, OX1 3PU, UK
| | - Andrew P Mackenzie
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187, Dresden, Germany. .,Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews, KY16 9SS, UK.
| | - Clifford W Hicks
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187, Dresden, Germany. .,School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, UK.
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14
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Beck S, Hampel A, Parcollet O, Ederer C, Georges A. Charge self-consistent electronic structure calculations with dynamical mean-field theory usingQuantum ESPRESSO, Wannier 90andTRIQS. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:235601. [PMID: 35276680 DOI: 10.1088/1361-648x/ac5d1c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
We present a fully charge self-consistent implementation of dynamical mean field theory (DMFT) combined with density functional theory (DFT) for electronic structure calculations of materials with strong electronic correlations. The implementation uses theQuantum ESPRESSOpackage for the DFT calculations, theWannier90code for the up-/down-folding and theTRIQSsoftware package for setting up and solving the DMFT equations. All components are available under open source licenses, are MPI-parallelized, fully integrated in the respective packages, and use an hdf5 archive interface to eliminate file parsing. We show benchmarks for three different systems that demonstrate excellent agreement with existing DFT + DMFT implementations in otherab initioelectronic structure codes.
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Affiliation(s)
- Sophie Beck
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, United States of America
| | - Alexander Hampel
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, United States of America
| | - Olivier Parcollet
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, United States of America
- Université Paris-Saclay, CNRS, CEA, Institut de Physique Théorique, 91191, Gif-sur-Yvette, France
| | - Claude Ederer
- Materials Theory, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland
| | - Antoine Georges
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, United States of America
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
- CPHT, CNRS, École Polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128 Palaiseau, France
- DQMP, Université de Genève, 24 Quai Ernest Ansermet, CH-1211 Genève, Switzerland
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15
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Hahn S, Sohn B, Kim M, Kim JR, Huh S, Kim Y, Kyung W, Kim M, Kim D, Kim Y, Noh TW, Shim JH, Kim C. Observation of Spin-Dependent Dual Ferromagnetism in Perovskite Ruthenates. PHYSICAL REVIEW LETTERS 2021; 127:256401. [PMID: 35029413 DOI: 10.1103/physrevlett.127.256401] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/11/2021] [Indexed: 06/14/2023]
Abstract
We performed in situ angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES (SARPES) experiments to investigate the relationship between electronic band structures and ferromagnetism in SrRuO_{3} (SRO) thin films. Our high quality ARPES and SARPES results show clear spin-lifted band structures. The spin polarization is strongly dependent on momentum around the Fermi level, whereas it becomes less dependent at high-binding energies. This experimental observation matches our dynamical mean-field theory results very well. As temperature increases from low to the Curie temperature, spin-splitting gap decreases and band dispersions become incoherent. Based on the ARPES study and theoretical calculation results, we found that SRO possesses spin-dependent electron correlations in which majority and minority spins are localized and itinerant, respectively. Our finding explains how ferromagnetism and electronic structure are connected, which has been under debate for decades in SRO.
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Affiliation(s)
- Sungsoo Hahn
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Byungmin Sohn
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Minjae Kim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Jeong Rae Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Soonsang Huh
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Younsik Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Wonshik Kyung
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Minsoo Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Donghan Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Youngdo Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Tae Won Noh
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Ji Hoon Shim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Changyoung Kim
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
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16
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Stepanov EA, Nomura Y, Lichtenstein AI, Biermann S. Orbital Isotropy of Magnetic Fluctuations in Correlated Electron Materials Induced by Hund's Exchange Coupling. PHYSICAL REVIEW LETTERS 2021; 127:207205. [PMID: 34860069 DOI: 10.1103/physrevlett.127.207205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 06/16/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Characterizing nonlocal magnetic fluctuations in materials with strong electronic Coulomb interactions remains one of the major outstanding challenges of modern condensed matter theory. In this Letter, we address the spatial symmetry and orbital structure of magnetic fluctuations in perovskite materials. To this aim, we develop a consistent multiorbital diagrammatic extension of dynamical mean-field theory, which we apply to an anisotropic three-orbital model of cubic t_{2g} symmetry. We find that the form of spatial spin fluctuations is governed by the local Hund's coupling. For small values of the coupling, magnetic fluctuations are anisotropic in orbital space, which reflects the symmetry of the considered t_{2g} model. Large Hund's coupling enhances collective spin excitations, which mixes orbital and spatial degrees of freedom, and magnetic fluctuations become orbitally isotropic. Remarkably, this effect can be seen only in two-particle quantities; single-particle observables remain anisotropic for any value of the Hund's coupling. Importantly, we find that the orbital isotropy can be induced both at half filling and for the case of four electrons per lattice site, where the magnetic instability is associated with different, antiferromagnetic and ferromagnetic, modes, respectively.
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Affiliation(s)
- Evgeny A Stepanov
- I. Institute of Theoretical Physics, University of Hamburg, Jungiusstrasse 9, 20355 Hamburg, Germany
- Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira Street 19, 620002 Ekaterinburg, Russia
| | - Yusuke Nomura
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Alexander I Lichtenstein
- I. Institute of Theoretical Physics, University of Hamburg, Jungiusstrasse 9, 20355 Hamburg, Germany
- Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira Street 19, 620002 Ekaterinburg, Russia
| | - Silke Biermann
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
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17
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Ahn C, Cavalleri A, Georges A, Ismail-Beigi S, Millis AJ, Triscone JM. Designing and controlling the properties of transition metal oxide quantum materials. NATURE MATERIALS 2021; 20:1462-1468. [PMID: 33941911 DOI: 10.1038/s41563-021-00989-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
This Perspective addresses the design, creation, characterization and control of synthetic quantum materials with strong electronic correlations. We show how emerging synergies between theoretical/computational approaches and materials design/experimental probes are driving recent advances in the discovery, understanding and control of new electronic behaviour in materials systems with interesting and potentially technologically important properties. The focus here is on transition metal oxides, where electronic correlations lead to a myriad of functional properties including superconductivity, magnetism, Mott transitions, multiferroicity and emergent behaviour at picoscale-designed interfaces. Current opportunities and challenges are also addressed, including possible new discoveries of non-equilibrium phenomena and optical control of correlated quantum phases of transition metal oxides.
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Affiliation(s)
| | - Andrea Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - Antoine Georges
- Collège de France, Paris, France
- CCQ-Flatiron Institute, New York, NY, USA
| | | | - Andrew J Millis
- CCQ-Flatiron Institute, New York, NY, USA
- Columbia University, New York, NY, USA
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18
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Maurya AK, Sarder MTH, Medhi A. Ground state of a three-band Hubbard model with Hund's coupling: Janus-faced behavior in presence of magnetic order. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:425603. [PMID: 34298529 DOI: 10.1088/1361-648x/ac1766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
We study the ground state of the three-band degenerate Hubbard model on a square lattice at integer fillings using the variational slave-spin mean field method. At half-filling, the method reproduces the well known result that the ground state is antiferromagnetic (AF) insulating at smaller values of Hubbard onsite repulsionU, while it becomes Mott insulating with Néel AF order at higherU. Away from half-filling, for two particles per site, we show that the model supports a ferromagnetic (FM) metallic state with fully polarized spins at sufficiently largeU. The FM state occurs irrespective of the value of Hund's couplingJ. The ferromagnetism atJ= 0 can be explained by the Stoner mechanism while that forJ> 0 is shown to arise from the superexchange process. At this band filling, the Hund's couplingJis known to have the Janus-faced effect on electronic correlations where it enhances correlations at smallerUwhile reducing it at higherU. We show that these two effects are separated by the paramagnetic (PM) to FM transition point. The former effect is obtained at the PM state while the latter occurs in the FM state. The FM phase also occurs for one particle per site but here Hund's couplingJreduces the effect of electronic correlations at allU.
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Affiliation(s)
- Arun Kumar Maurya
- Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695551, India
| | | | - Amal Medhi
- Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695551, India
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19
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Chronister A, Pustogow A, Kikugawa N, Sokolov DA, Jerzembeck F, Hicks CW, Mackenzie AP, Bauer ED, Brown SE. Evidence for even parity unconventional superconductivity in Sr 2RuO 4. Proc Natl Acad Sci U S A 2021; 118:e2025313118. [PMID: 34161272 PMCID: PMC8237678 DOI: 10.1073/pnas.2025313118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unambiguous identification of the superconducting order parameter symmetry in [Formula: see text] has remained elusive for more than a quarter century. While a chiral p-wave ground state analogue to superfluid 3He-A was ruled out only very recently, other proposed triplet-pairing scenarios are still viable. Establishing the condensate magnetic susceptibility reveals a sharp distinction between even-parity (singlet) and odd-parity (triplet) pairing since the superconducting condensate is magnetically polarizable only in the latter case. Here field-dependent 17O Knight shift measurements, being sensitive to the spin polarization, are compared to previously reported specific heat measurements for the purpose of distinguishing the condensate contribution from that due to quasiparticles. We conclude that the shift results can be accounted for entirely by the expected field-induced quasiparticle response. An upper bound for the condensate magnetic response of <10% of the normal state susceptibility is sufficient to exclude all purely odd-parity candidates.
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Affiliation(s)
- Aaron Chronister
- Department of Physics & Astronomy, University of California, Los Angeles, CA 90095;
| | - Andrej Pustogow
- Department of Physics & Astronomy, University of California, Los Angeles, CA 90095;
| | - Naoki Kikugawa
- Cryogenic Center for Liquid Hydrogen and Materials Science, National Institute for Materials Science, Tsukuba 305-0003, Japan
| | - Dmitry A Sokolov
- Physics of Quantum Materials Department, Max Planck Institute for Chemical Physics of Solids, Dresden 01187, Germany
| | - Fabian Jerzembeck
- Physics of Quantum Materials Department, Max Planck Institute for Chemical Physics of Solids, Dresden 01187, Germany
| | - Clifford W Hicks
- Physics of Quantum Materials Department, Max Planck Institute for Chemical Physics of Solids, Dresden 01187, Germany
- School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Andrew P Mackenzie
- Physics of Quantum Materials Department, Max Planck Institute for Chemical Physics of Solids, Dresden 01187, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, United Kingdom
| | - Eric D Bauer
- Materials Physics and Applications, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Stuart E Brown
- Department of Physics & Astronomy, University of California, Los Angeles, CA 90095;
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20
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Ryee S, Han MJ, Choi S. Hund Physics Landscape of Two-Orbital Systems. PHYSICAL REVIEW LETTERS 2021; 126:206401. [PMID: 34110184 DOI: 10.1103/physrevlett.126.206401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 02/10/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Motivated by the recent discovery of superconductivity in infinite-layer nickelates RE_{1-δ}Sr_{δ}NiO_{2} (RE=Nd, Pr), we study the role of Hund coupling J in a quarter-filled two-orbital Hubbard model, which has been on the periphery of the attention. A region of negative effective Coulomb interaction of this model is revealed to be differentiated from three- and five-orbital models in their typical Hund metal active fillings. We identify distinctive regimes including four different correlated metals, one of which stems from the proximity to a Mott insulator, while the other three, which we call "intermediate" metal, weak Hund metal, and valence-skipping metal, from the effect of J being away from Mottness. Defining criteria characterizing these metals is suggested, establishing the existence of Hund metallicity in two-orbital systems.
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Affiliation(s)
- Siheon Ryee
- Department of Physics, KAIST, Daejeon 34141, Republic of Korea
| | - Myung Joon Han
- Department of Physics, KAIST, Daejeon 34141, Republic of Korea
| | - Sangkook Choi
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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21
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Kang CJ, Kotliar G. Optical Properties of the Infinite-Layer La_{1-x}Sr_{x}NiO_{2} and Hidden Hund's Physics. PHYSICAL REVIEW LETTERS 2021; 126:127401. [PMID: 33834805 DOI: 10.1103/physrevlett.126.127401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
We investigate the optical properties of the normal state of the infinite-layer La_{1-x}Sr_{x}NiO_{2} using density functional theory plus dynamical mean-field theory. We find a correlated metal which exhibits substantial transfer of spectral weight to high energies relative to the density functional theory. The correlations are not due to Mott physics, which would suppress the charge fluctuations and the integrated optical spectral weight as we approach a putative insulating state. Instead, we find the unusual situation, that the integrated optical spectral weight decreases with doping and increases with increasing temperature. We contrast this with the coherent component of the optical conductivity, which decreases with increasing temperature as a result of a coherence-incoherence crossover. Our studies reveal that the effective crystal field splitting is dynamical and increases strongly at low frequency. This leads to a picture of a Hund's metallic state, where dynamical orbital fluctuations are visible at intermediate energies, while at low energies a Fermi surface with primarily d_{x^{2}-y^{2}} character emerges. The infinite-layer nickelates are thus in an intermediate position between the iron based high temperature superconductors where multiorbital Hund's physics dominates and a one-band system such as the cuprates. To capture this physics we propose a low-energy two-band model with atom centered e_{g} states.
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Affiliation(s)
- Chang-Jong Kang
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856, USA
- Department of Physics, Chungnam National University, Daejeon 34134, South Korea
| | - Gabriel Kotliar
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856, USA
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
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22
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Deng X, Stadler KM, Haule K, Lee SSB, Weichselbaum A, von Delft J, Kotliar G. Reply to: "Extracting Kondo temperature of strongly-correlated systems from the inverse local magnetic susceptibility". Nat Commun 2021; 12:1445. [PMID: 33664248 PMCID: PMC7933365 DOI: 10.1038/s41467-021-21643-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 01/29/2021] [Indexed: 02/04/2023] Open
Affiliation(s)
- Xiaoyu Deng
- grid.430387.b0000 0004 1936 8796Department of Physics and Astronomy, Rutgers University, Piscataway, NJ USA
| | - Katharina M. Stadler
- grid.5252.00000 0004 1936 973XPhysics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitat München, München, Germany
| | - Kristjan Haule
- grid.430387.b0000 0004 1936 8796Department of Physics and Astronomy, Rutgers University, Piscataway, NJ USA
| | - Seung-Sup B. Lee
- grid.5252.00000 0004 1936 973XPhysics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitat München, München, Germany
| | - Andreas Weichselbaum
- grid.5252.00000 0004 1936 973XPhysics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitat München, München, Germany ,grid.202665.50000 0001 2188 4229Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY USA
| | - Jan von Delft
- grid.5252.00000 0004 1936 973XPhysics Department, Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universitat München, München, Germany
| | - Gabriel Kotliar
- grid.430387.b0000 0004 1936 8796Department of Physics and Astronomy, Rutgers University, Piscataway, NJ USA ,grid.202665.50000 0001 2188 4229Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY USA
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23
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Direct observation of kink evolution due to Hund's coupling on approach to metal-insulator transition in NiS 2-xSe x. Nat Commun 2021; 12:1208. [PMID: 33623023 PMCID: PMC7902648 DOI: 10.1038/s41467-021-21460-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 01/15/2021] [Indexed: 11/24/2022] Open
Abstract
Understanding characteristic energy scales is a fundamentally important issue in the study of strongly correlated systems. In multiband systems, an energy scale is affected not only by the effective Coulomb interaction but also by the Hund’s coupling. Direct observation of such energy scale has been elusive so far in spite of extensive studies. Here, we report the observation of a kink structure in the low energy dispersion of NiS2−xSex and its characteristic evolution with x, by using angle resolved photoemission spectroscopy. Dynamical mean field theory calculation combined with density functional theory confirms that this kink originates from Hund’s coupling. We find that the abrupt deviation from the Fermi liquid behavior in the electron self-energy results in the kink feature at low energy scale and that the kink is directly related to the coherence-incoherence crossover temperature scale. Our results mark the direct observation of the evolution of the characteristic temperature scale via kink features in the spectral function, which is the hallmark of Hund’s physics in the multiorbital system. A decisive spectroscopic evidence of the Hund’s coupling energy scale in multi-orbital correlated systems has been lacking. Here, the authors identify a kink feature due to Hund´s coupling in the spectral function of NiS2xSex as they track its evolution across the Mott-insulator transition.
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24
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Ruf JP, Paik H, Schreiber NJ, Nair HP, Miao L, Kawasaki JK, Nelson JN, Faeth BD, Lee Y, Goodge BH, Pamuk B, Fennie CJ, Kourkoutis LF, Schlom DG, Shen KM. Strain-stabilized superconductivity. Nat Commun 2021; 12:59. [PMID: 33397949 PMCID: PMC7782483 DOI: 10.1038/s41467-020-20252-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/19/2020] [Indexed: 11/09/2022] Open
Abstract
Superconductivity is among the most fascinating and well-studied quantum states of matter. Despite over 100 years of research, a detailed understanding of how features of the normal-state electronic structure determine superconducting properties has remained elusive. For instance, the ability to deterministically enhance the superconducting transition temperature by design, rather than by serendipity, has been a long sought-after goal in condensed matter physics and materials science, but achieving this objective may require new tools, techniques and approaches. Here, we report the transmutation of a normal metal into a superconductor through the application of epitaxial strain. We demonstrate that synthesizing RuO2 thin films on (110)-oriented TiO2 substrates enhances the density of states near the Fermi level, which stabilizes superconductivity under strain, and suggests that a promising strategy to create new transition-metal superconductors is to apply judiciously chosen anisotropic strains that redistribute carriers within the low-energy manifold of d orbitals.
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Affiliation(s)
- J P Ruf
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA.
| | - H Paik
- Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials, Cornell University, Ithaca, NY, 14853, USA.,Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - N J Schreiber
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - H P Nair
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - L Miao
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA
| | - J K Kawasaki
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA.,Department of Materials Science and Engineering, University of Wisconsin, Madison, WI, 53706, USA
| | - J N Nelson
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA
| | - B D Faeth
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA.,Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials, Cornell University, Ithaca, NY, 14853, USA
| | - Y Lee
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA
| | - B H Goodge
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA.,Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
| | - B Pamuk
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
| | - C J Fennie
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
| | - L F Kourkoutis
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA.,Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
| | - D G Schlom
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA.,Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA.,Leibniz-Institut für Kristallzüchtung, Max-Born-Str. 2, Berlin, 12489, Germany
| | - K M Shen
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA. .,Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA.
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25
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Karp J, Bramberger M, Grundner M, Schollwöck U, Millis AJ, Zingl M. Sr_{2}MoO_{4} and Sr_{2}RuO_{4}: Disentangling the Roles of Hund's and van Hove Physics. PHYSICAL REVIEW LETTERS 2020; 125:166401. [PMID: 33124840 DOI: 10.1103/physrevlett.125.166401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 09/22/2020] [Indexed: 06/11/2023]
Abstract
Sr_{2}MoO_{4} is isostructural to the unconventional superconductor Sr_{2}RuO_{4} but with two electrons instead of two holes in the Mo/Ru-t_{2g} orbitals. Both materials are Hund's metals, but while Sr_{2}RuO_{4} has a van Hove singularity in close proximity to the Fermi surface, the van Hove singularity of Sr_{2}MoO_{4} is far from the Fermi surface. By using density functional plus dynamical mean-field theory, we determine the relative influence of van Hove and Hund's metal physics on the correlation properties. We show that theoretically predicted signatures of Hund's metal physics occur on the occupied side of the electronic spectrum of Sr_{2}MoO_{4}, identifying Sr_{2}MoO_{4} as an ideal candidate system for a direct experimental confirmation of the theoretical concept of Hund's metals via photoemission spectroscopy.
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Affiliation(s)
- Jonathan Karp
- Department of Applied Physics and Applied Math, Columbia University, New York, New York 10027, USA
| | - Max Bramberger
- Arnold Sommerfeld Center of Theoretical Physics, Department of Physics, University of Munich, Theresienstrasse 37, 80333 Munich, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, 80799 Munich, Germany
| | - Martin Grundner
- Arnold Sommerfeld Center of Theoretical Physics, Department of Physics, University of Munich, Theresienstrasse 37, 80333 Munich, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, 80799 Munich, Germany
| | - Ulrich Schollwöck
- Arnold Sommerfeld Center of Theoretical Physics, Department of Physics, University of Munich, Theresienstrasse 37, 80333 Munich, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, 80799 Munich, Germany
| | - Andrew J Millis
- Department of Physics, Columbia University, New York, New York 10027, USA
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
| | - Manuel Zingl
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
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26
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Pourovskii LV, Mravlje J, Pozzo M, Alfè D. Electronic correlations and transport in iron at Earth's core conditions. Nat Commun 2020; 11:4105. [PMID: 32796852 PMCID: PMC7429499 DOI: 10.1038/s41467-020-18003-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 07/21/2020] [Indexed: 11/20/2022] Open
Abstract
The transport properties of iron under Earth’s inner core conditions are essential input for the geophysical modelling but are poorly constrained experimentally. Here we show that the thermal and electrical conductivity of iron at those conditions remains high even if the electron-electron-scattering (EES) is properly taken into account. This result is obtained by ab initio simulations taking into account consistently both thermal disorder and electronic correlations. Thermal disorder suppresses the non-Fermi-liquid behavior of the body-centered cubic iron phase, hence, reducing the EES; the total calculated thermal conductivity of this phase is 220 Wm−1 K−1 with the EES reduction not exceeding 20%. The EES and electron-lattice scattering are intertwined resulting in breaking of the Matthiessen’s rule with increasing EES. In the hexagonal close-packed iron the EES is also not increased by thermal disorder and remains weak. Our main finding thus holds for the both likely iron phases in the inner core. The heat and electrical conductivity of Earth’s core matter represent key input quantities for geophysical models of the Earth’s core evolution and geodynamo. Here, the authors show how the scattering due to interactions between electrons has a relatively weak impact on the electrical and thermal conductivities of iron at core conditions.
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Affiliation(s)
- L V Pourovskii
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128, Palaiseau, France. .,Collège de France, 11 place Marcelin Berthelot, 75005, Paris, France.
| | - J Mravlje
- Jozef Stefan Institute, SI-1000, Ljubljana, Slovenia
| | - M Pozzo
- Department of Earth Sciences and London Centre for Nanotechnology, University College London, Gower Street, London, WC1E 6BT, UK
| | - D Alfè
- Department of Earth Sciences and London Centre for Nanotechnology, University College London, Gower Street, London, WC1E 6BT, UK.,Dipartimento di Fisica Ettore Pancini, Università di Napoli Federico II, Monte S. Angelo, I-80126, Napoli, Italy
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27
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Wang S, Scholes GD, Hsu LY. Coherent-to-Incoherent Transition of Molecular Fluorescence Controlled by Surface Plasmon Polaritons. J Phys Chem Lett 2020; 11:5948-5955. [PMID: 32619095 DOI: 10.1021/acs.jpclett.0c01680] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigate the coherent-to-incoherent transition of molecular fluorescence of a chromophore above a silver surface (including bulk and thin-film systems) and explore the distance dependence of fluorescence rate enhancement. In the framework of macroscopic quantum electrodynamics, we generalize our previous theory to include multiple vibrational modes. The present theory can accurately describe quantum dynamics from the coherent limit to the incoherent limit. Moreover, we introduce a new concept Incoherent Index to quantify the degree of quantum coherence and demonstrate that the coherent-to-incoherent transition can be controlled by the dielectric environment and the molecule-silver distance. In addition, our theory indicates that strong molecule-photon (polariton) coupling can be achieved by virtue of small Huang-Rhys factors, large transition dipole moments, and appropriate dielectric material design. The present study provides a new direction for engineering light-matter interactions in polaritonic chemistry.
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Affiliation(s)
- Siwei Wang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Liang-Yan Hsu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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28
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Wang Y, Walter E, Lee SSB, Stadler KM, von Delft J, Weichselbaum A, Kotliar G. Global Phase Diagram of a Spin-Orbital Kondo Impurity Model and the Suppression of Fermi-Liquid Scale. PHYSICAL REVIEW LETTERS 2020; 124:136406. [PMID: 32302177 DOI: 10.1103/physrevlett.124.136406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/28/2020] [Indexed: 06/11/2023]
Abstract
Many correlated metallic materials are described by Landau Fermi-liquid theory at low energies, but for Hund metals the Fermi-liquid coherence scale T_{FL} is found to be surprisingly small. In this Letter, we study the simplest impurity model relevant for Hund metals, the three-channel spin-orbital Kondo model, using the numerical renormalization group (NRG) method and compute its global phase diagram. In this framework, T_{FL} becomes arbitrarily small close to two new quantum critical points that we identify by tuning the spin or spin-orbital Kondo couplings into the ferromagnetic regimes. We find quantum phase transitions to a singular Fermi-liquid or a novel non-Fermi-liquid phase. The new non-Fermi-liquid phase shows frustrated behavior involving alternating overscreenings in spin and orbital sectors, with universal power laws in the spin (ω^{-1/5}), orbital (ω^{1/5}) and spin-orbital (ω^{1}) dynamical susceptibilities. These power laws, and the NRG eigenlevel spectra, can be fully understood using conformal field theory arguments, which also clarify the nature of the non-Fermi-liquid phase.
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Affiliation(s)
- Y Wang
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - E Walter
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - S-S B Lee
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - K M Stadler
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - J von Delft
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - A Weichselbaum
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - G Kotliar
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856, USA
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29
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Kugler FB, Zingl M, Strand HUR, Lee SSB, von Delft J, Georges A. Strongly Correlated Materials from a Numerical Renormalization Group Perspective: How the Fermi-Liquid State of Sr_{2}RuO_{4} Emerges. PHYSICAL REVIEW LETTERS 2020; 124:016401. [PMID: 31976705 DOI: 10.1103/physrevlett.124.016401] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Indexed: 06/10/2023]
Abstract
The crossover from fluctuating atomic constituents to a collective state as one lowers temperature or energy is at the heart of the dynamical mean-field theory description of the solid state. We demonstrate that the numerical renormalization group is a viable tool to monitor this crossover in a real-materials setting. The renormalization group flow from high to arbitrarily small energy scales clearly reveals the emergence of the Fermi-liquid state of Sr_{2}RuO_{4}. We find a two-stage screening process, where orbital fluctuations are screened at much higher energies than spin fluctuations, and Fermi-liquid behavior, concomitant with spin coherence, below a temperature of 25 K. By computing real-frequency correlation functions, we directly observe this spin-orbital scale separation and show that the van Hove singularity drives strong orbital differentiation. We extract quasiparticle interaction parameters from the low-energy spectrum and find an effective attraction in the spin-triplet sector.
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Affiliation(s)
- Fabian B Kugler
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - Manuel Zingl
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
| | - Hugo U R Strand
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
| | - Seung-Sup B Lee
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - Jan von Delft
- Arnold Sommerfeld Center for Theoretical Physics, Center for NanoScience, and Munich Center for Quantum Science and Technology, Ludwig-Maximilians-Universität München, 80333 Munich, Germany
| | - Antoine Georges
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
- Centre de Physique Théorique, CNRS, Ecole Polytechnique, IP Paris, 91128 Palaiseau, France
- Department of Quantum Matter Physics, University of Geneva, 1211 Geneva 4, Switzerland
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30
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Rømer AT, Scherer DD, Eremin IM, Hirschfeld PJ, Andersen BM. Knight Shift and Leading Superconducting Instability from Spin Fluctuations in Sr_{2}RuO_{4}. PHYSICAL REVIEW LETTERS 2019; 123:247001. [PMID: 31922834 DOI: 10.1103/physrevlett.123.247001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Indexed: 06/10/2023]
Abstract
Recent nuclear magnetic resonance studies [A. Pustogow et al., Nature 574, 72 (2019)] have challenged the prevalent chiral triplet pairing scenario proposed for Sr_{2}RuO_{4}. To provide guidance from microscopic theory as to which other pair states might be compatible with the new data, we perform a detailed theoretical study of spin fluctuation mediated pairing for this compound. We map out the phase diagram as a function of spin-orbit coupling, interaction parameters, and band structure properties over physically reasonable ranges, comparing when possible with photoemission and inelastic neutron scattering data information. We find that even-parity pseudospin singlet solutions dominate large regions of the phase diagram, but in certain regimes spin-orbit coupling favors a near-nodal odd-parity triplet superconducting state, which is either helical or chiral depending on the proximity of the γ band to the van Hove points. A surprising near degeneracy of the nodal s^{'} and d_{x^{2}-y^{2}} wave solutions leads to the possibility of a near-nodal time-reversal symmetry broken s^{'}+id_{x^{2}-y^{2}} pair state. Predictions for the temperature dependence of the Knight shift for fields in and out of plane are presented for all states.
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Affiliation(s)
- A T Rømer
- Niels Bohr Institute, University of Copenhagen, Vibenhuset, Lyngbyvej 2, DK-2100 Copenhagen, Denmark
- Institut Laue-Langevin, 71 avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France
| | - D D Scherer
- Niels Bohr Institute, University of Copenhagen, Vibenhuset, Lyngbyvej 2, DK-2100 Copenhagen, Denmark
| | - I M Eremin
- Institut für Theoretische Physik III, Ruhr-Universität Bochum, D-44801 Bochum, Germany
- National University of Science and Technology MISiS, 119049 Moscow, Russia
| | - P J Hirschfeld
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - B M Andersen
- Niels Bohr Institute, University of Copenhagen, Vibenhuset, Lyngbyvej 2, DK-2100 Copenhagen, Denmark
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31
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Gingras O, Nourafkan R, Tremblay AMS, Côté M. Superconducting Symmetries of Sr_{2}RuO_{4} from First-Principles Electronic Structure. PHYSICAL REVIEW LETTERS 2019; 123:217005. [PMID: 31809152 DOI: 10.1103/physrevlett.123.217005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Indexed: 06/10/2023]
Abstract
Although correlated electronic-structure calculations explain very well the normal state of Sr_{2}RuO_{4}, its superconducting symmetry is still unknown. Here we construct the spin and charge fluctuation pairing interactions based on its correlated normal state. Correlations significantly reduce ferromagnetic in favor of antiferromagnetic fluctuations and increase interorbital pairing. From the normal-state Eliashberg equations, we find spin-singlet d-wave pairing close to magnetic instabilities. Away from these instabilities, where charge fluctuations increase, we find two time-reversal symmetry-breaking spin triplets: an odd-frequency s wave, and a doubly degenerate interorbital pairing between d_{xy} and (d_{yz},d_{xz}).
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Affiliation(s)
- O Gingras
- Département de Physique and Regroupement Québécois sur les Matériaux de Pointe, Université de Montréal, C. P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada
| | - R Nourafkan
- Département de Physique, Institut quantique, Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - A-M S Tremblay
- Département de Physique, Institut quantique, Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
- Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
| | - M Côté
- Département de Physique and Regroupement Québécois sur les Matériaux de Pointe, Université de Montréal, C. P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada
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32
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Bertinshaw J, Gurung N, Jorba P, Liu H, Schmid M, Mantadakis DT, Daghofer M, Krautloher M, Jain A, Ryu GH, Fabelo O, Hansmann P, Khaliullin G, Pfleiderer C, Keimer B, Kim BJ. Unique Crystal Structure of Ca_{2}RuO_{4} in the Current Stabilized Semimetallic State. PHYSICAL REVIEW LETTERS 2019; 123:137204. [PMID: 31697510 DOI: 10.1103/physrevlett.123.137204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 07/26/2019] [Indexed: 06/10/2023]
Abstract
The electric-current stabilized semimetallic state in the quasi-two-dimensional Mott insulator Ca_{2}RuO_{4} exhibits an exceptionally strong diamagnetism. Through a comprehensive study using neutron and x-ray diffraction, we show that this nonequilibrium phase assumes a crystal structure distinct from those of equilibrium metallic phases realized in the ruthenates by chemical doping, high pressure, and epitaxial strain, which in turn leads to a distinct electronic band structure. Dynamical mean field theory calculations based on the crystallographically refined atomic coordinates and realistic Coulomb repulsion parameters indicate a semimetallic state with partially gapped Fermi surface. Our neutron diffraction data show that the nonequilibrium behavior is homogeneous, with antiferromagnetic long-range order completely suppressed. These results provide a new basis for theoretical work on the origin of the unusual nonequilibrium diamagnetism in Ca_{2}RuO_{4}.
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Affiliation(s)
- J Bertinshaw
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - N Gurung
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - P Jorba
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
| | - H Liu
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - M Schmid
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - D T Mantadakis
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - M Daghofer
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - M Krautloher
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - A Jain
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
| | - G H Ryu
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - O Fabelo
- Institut Laue Langevin, BP 156, F-38042 Grenoble cedex 9, France
| | - P Hansmann
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzerstr Straße 40, D-01187 Dresden, Germany
| | - G Khaliullin
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - C Pfleiderer
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
| | - B Keimer
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - B J Kim
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Department of Physics, Pohang University of Science and Technology, Pohang 790-784, South Korea
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), 77 Cheongam-Ro, Pohang 790-784, South Korea
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33
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Pourovskii LV. Electronic correlations in dense iron: from moderate pressure to Earth's core conditions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:373001. [PMID: 31167170 DOI: 10.1088/1361-648x/ab274f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We discuss the role of dynamical many-electron effects in the physics of iron and iron-rich solid alloys under applied pressure on the basis of recent ab initio studies employing the dynamical mean-field theory (DMFT). We review in detail two particularly interesting regimes: first, a moderate pressure range up to 60 GPa and, second, the ultra-high pressure of about 360 GPa expected inside the solid inner core of Earth. Electronic correlations in iron under the moderate pressure of several tens GPa are discussed in the first section. DMFT-based methods predict an enhancement of electronic correlations at the pressure-induced body-centered cubic α to hexagonal close-packed [Formula: see text] phase transition. In particular, the electronic effective mass, scattering rate and electron-electron contribution to the electrical resistivity undergo a step-wise increase at the transition point. One also finds a significant many-body correction to the [Formula: see text]-Fe equation of state, thus clarifying the origin of discrepancies between previous DFT studies and experiment. An electronic topological transition is predicted to be induced in [Formula: see text]-Fe by many-electron effects; its experimental signatures are analyzed. The next section focuses on the geophysically relevant pressure-temperature regime of the Earth's inner core (EIC) corresponding to the extreme pressure of 360 GPa combined with temperatures up to 6000 K. The three iron allotropes ([Formula: see text], [Formula: see text] and face-centered-cubic [Formula: see text]) previously proposed as possible stable phases at such conditions are found to exhibit qualitatively different many-electron effects as evidenced by a strongly non-Fermi-liquid metallic state of [Formula: see text]-Fe and an almost perfect Fermi liquid in the case of [Formula: see text]-Fe. A recent active discussion on the electronic state and transport properties of [Formula: see text]-Fe at the EIC conditions is reviewed in details. Estimations for the dynamical many-electron contribution to the relative phase stability are presented. We also discuss the impact of a Ni admixture, which is expected to be present in the core matter. We conclude by outlining some limitation of the present DMFT-based framework relevant for studies of iron-base systems as well as perspective directions for further development.
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Affiliation(s)
- Leonid V Pourovskii
- CPHT, CNRS, Ecole Polytechnique, IP Paris, F-91128 Palaiseau, France. Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
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34
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Signatures of Mottness and Hundness in archetypal correlated metals. Nat Commun 2019; 10:2721. [PMID: 31221960 PMCID: PMC6586627 DOI: 10.1038/s41467-019-10257-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 04/26/2019] [Indexed: 02/06/2023] Open
Abstract
Physical properties of multi-orbital materials depend not only on the strength of the effective interactions among the valence electrons but also on their type. Strong correlations are caused by either Mott physics that captures the Coulomb repulsion among charges, or Hund physics that aligns the spins in different orbitals. We identify four energy scales marking the onset and the completion of screening in orbital and spin channels. The differences in these scales, which are manifest in the temperature dependence of the local spectrum and of the charge, spin and orbital susceptibilities, provide clear signatures distinguishing Mott and Hund physics. We illustrate these concepts with realistic studies of two archetypal strongly correlated materials, and corroborate the generality of our conclusions with a model Hamiltonian study.
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35
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Facio JI, Cornaglia PS. Hund's metal regimes and orbital selective Mott transitions in three band systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:245602. [PMID: 30844779 DOI: 10.1088/1361-648x/ab0dce] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We analyze the electronic properties of interacting crystal field split three band systems. Using a rotationally invariant slave boson approach we analyze the behavior of the electronic mass renormalization as a function of the intralevel repulsion U, the Hund's coupling J, the crystal field splitting, and the number of electrons per site n. We first focus on the case in which two of the bands are identical and the levels of the third one are shifted by [Formula: see text] with respect to the former. We find an increasing quasiparticle mass differentiation between the bands, for system away from half-filling (n = 3), as the Hubbard interaction U is increased. This leads to orbital selective Mott transitions where either the higher energy band (for 4 > n > 3) or the lower energy degenerate bands (2 < n < 3) become insulating for U larger than a critical interaction [Formula: see text]. Away from the half-filled case [Formula: see text] there is a wide range of parameters for [Formula: see text] where the system presents a Hund's metal phase with the physics dominated by the local high spin multiplets. Finally, we study the fate of the n = 2 Hund's metal as the energy splitting between orbitals is increased for different possible crystal distortions. We find a strong sensitivity of the Hund's metal regime to crystal fields due to the opposing effects of J and the crystal field splittings on the charge distribution between the bands.
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Affiliation(s)
- Jorge I Facio
- Centro Atómico Bariloche and Instituto Balseiro, CNEA, CONICET, (8400) Bariloche, Argentina. Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany
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36
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Steffens P, Sidis Y, Kulda J, Mao ZQ, Maeno Y, Mazin II, Braden M. Spin Fluctuations in Sr_{2}RuO_{4} from Polarized Neutron Scattering: Implications for Superconductivity. PHYSICAL REVIEW LETTERS 2019; 122:047004. [PMID: 30768293 DOI: 10.1103/physrevlett.122.047004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Indexed: 06/09/2023]
Abstract
Triplet pairing in Sr_{2}RuO_{4} was initially suggested based on the hypothesis of strong ferromagnetic spin fluctuations. Using polarized inelastic neutron scattering, we accurately determine the full spectrum of spin fluctuations in Sr_{2}RuO_{4}. Besides the well-studied incommensurate magnetic fluctuations, we do find a sizable quasiferromagnetic signal, quantitatively consistent with all macroscopic and microscopic probes. We use this result to address the possibility of magnetically driven triplet superconductivity in Sr_{2}RuO_{4}. We conclude that, even though the quasiferromagnetic signal is stronger and sharper than previously anticipated, spin fluctuations alone are not enough to generate a triplet state strengthening the need for additional interactions or an alternative pairing scenario.
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Affiliation(s)
- P Steffens
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany
- Institut Laue Langevin, 71 avenue des Martyrs, 38000 Grenoble, France
| | - Y Sidis
- Laboratoire Léon Brillouin, C.E.A./C.N.R.S., F-91191 Gif-sur-Yvette CEDEX, France
| | - J Kulda
- Institut Laue Langevin, 71 avenue des Martyrs, 38000 Grenoble, France
| | - Z Q Mao
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Department of Physics, Tulane University, New Orleans, Louisiana 70118, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Y Maeno
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - I I Mazin
- Code 6393, Naval Research Laboratory, Washington, DC 20375, USA
| | - M Braden
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany
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37
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Lee TH, Chubukov A, Miao H, Kotliar G. Pairing Mechanism in Hund's Metal Superconductors and the Universality of the Superconducting Gap to Critical Temperature Ratio. PHYSICAL REVIEW LETTERS 2018; 121:187003. [PMID: 30444397 DOI: 10.1103/physrevlett.121.187003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/20/2018] [Indexed: 06/09/2023]
Abstract
We analyze a simple model containing the physical ingredients of a Hund's metal, the local spin fluctuations with power-law correlators, (Ω_{0}/|Ω|)^{γ}, with γ greater than one, interacting with electronic quasiparticles. While the critical temperature and the gap change significantly with varying parameters, the 2Δ_{max}/k_{B}T_{c} remains close to twice the BCS value in agreement with experimental observations in the iron-based superconductors (FeSC).
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Affiliation(s)
- Tsung-Han Lee
- Physics and Astronomy Department, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Andrey Chubukov
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Hu Miao
- Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Gabriel Kotliar
- Physics and Astronomy Department, Rutgers University, Piscataway, New Jersey 08854, USA
- Brookhaven National Laboratory, Upton, New York 11973, USA
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38
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Boehnke L, Werner P, Lechermann F. Multi-orbital nature of the spin fluctuations in Sr
2
RuO
4. ACTA ACUST UNITED AC 2018. [DOI: 10.1209/0295-5075/122/57001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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39
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Tomczak JM. Thermoelectricity in correlated narrow-gap semiconductors. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:183001. [PMID: 29633717 DOI: 10.1088/1361-648x/aab284] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We review many-body effects, their microscopic origin, as well as their impact on thermoelectricity in correlated narrow-gap semiconductors. Members of this class-such as FeSi and FeSb2-display an unusual temperature dependence in various observables: insulating with large thermopowers at low temperatures, they turn bad metals at temperatures much smaller than the size of their gaps. This insulator-to-metal crossover is accompanied by spectral weight-transfers over large energies in the optical conductivity and by a gradual transition from activated to Curie-Weiss-like behaviour in the magnetic susceptibility. We show a retrospective of the understanding of these phenomena, discuss the relation to heavy-fermion Kondo insulators-such as Ce3Bi4Pt3 for which we present new results-and propose a general classification of paramagnetic insulators. From the latter, FeSi emerges as an orbital-selective Kondo insulator. Focussing on intermetallics such as silicides, antimonides, skutterudites, and Heusler compounds we showcase successes and challenges for the realistic simulation of transport properties in the presence of electronic correlations. Further, we explore new avenues in which electronic correlations may contribute to the improvement of thermoelectric performance.
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Affiliation(s)
- Jan M Tomczak
- Institute of Solid State Physics, TU Wien, A-1040 Vienna, Austria
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40
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Kim M, Mravlje J, Ferrero M, Parcollet O, Georges A. Spin-Orbit Coupling and Electronic Correlations in Sr_{2}RuO_{4}. PHYSICAL REVIEW LETTERS 2018; 120:126401. [PMID: 29694056 DOI: 10.1103/physrevlett.120.126401] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 02/20/2018] [Indexed: 06/08/2023]
Abstract
We investigate the interplay of spin-orbit coupling (SOC) and electronic correlations in Sr_{2}RuO_{4} using dynamical mean-field theory. We find that SOC does not affect the correlation-induced renormalizations, which validates Hund's metal picture of ruthenates even in the presence of the sizable SOC relevant to these materials. Nonetheless, SOC is found to change significantly the electronic structure at k points where a degeneracy applies in its absence. We explain why these two observations are consistent with one another and calculate the effects of SOC on the correlated electronic structure. The magnitude of these effects is found to depend on the energy of the quasiparticle state under consideration, leading us to introduce the notion of an energy-dependent quasiparticle spin-orbit coupling λ^{*}(ω). This notion is generally applicable to all materials in which both the spin-orbit coupling and electronic correlations are sizable.
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Affiliation(s)
- Minjae Kim
- Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau, France
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - Jernej Mravlje
- Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Michel Ferrero
- Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau, France
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - Olivier Parcollet
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
- Institut de Physique Théorique (IPhT), CEA, CNRS, 91191 Gif-sur-Yvette, France
| | - Antoine Georges
- Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau, France
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth avenue, New York, New York 10010, USA
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
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41
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Lo Vecchio I, Baldassarre L, Di Pietro P, Giorgianni F, Marsi M, Perucchi A, Schade U, Lanzara A, Lupi S. Orbital dependent coherence temperature and optical anisotropy of V 2O 3 quasiparticles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:345602. [PMID: 28665290 DOI: 10.1088/1361-648x/aa7cd7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on an orbital and temperature dependent study of the onset of coherent quasiparticles in V2O3 single crystal. By using polarized infrared spectroscopy we demonstrate that the electronic coherence temperature is strongly orbital dependent, being about 400 K for [Formula: see text] orbitals and 500 K for the [Formula: see text]. This suggests that V2O3 low energy electrodynamics can be described in terms of two electron liquids differently renormalized by electronic correlations.
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Affiliation(s)
- I Lo Vecchio
- Dipartimento di Fisica, 'Sapienza' Università di Roma, Piazzale A. Moro 2, I-00185 Roma, Italy. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
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42
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Inabayashi M, Doi Y, Wakeshima M, Hinatsu Y. Magnetic interactions in praseodymium ruthenate Pr 3 RuO 7 with fluorite-related structure. J SOLID STATE CHEM 2017. [DOI: 10.1016/j.jssc.2017.03.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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43
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Sutter D, Fatuzzo CG, Moser S, Kim M, Fittipaldi R, Vecchione A, Granata V, Sassa Y, Cossalter F, Gatti G, Grioni M, Rønnow HM, Plumb NC, Matt CE, Shi M, Hoesch M, Kim TK, Chang TR, Jeng HT, Jozwiak C, Bostwick A, Rotenberg E, Georges A, Neupert T, Chang J. Hallmarks of Hunds coupling in the Mott insulator Ca 2RuO 4. Nat Commun 2017; 8:15176. [PMID: 28474681 PMCID: PMC5424259 DOI: 10.1038/ncomms15176] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/03/2017] [Indexed: 11/20/2022] Open
Abstract
A paradigmatic case of multi-band Mott physics including spin-orbit and Hund's coupling is realized in Ca2RuO4. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy electronic structure. Here we provide—using angle-resolved photoemission electron spectroscopy—the band structure of the paramagnetic insulating phase of Ca2RuO4 and show how it features several distinct energy scales. Comparison to a simple analysis of atomic multiplets provides a quantitative estimate of the Hund's coupling J=0.4 eV. Furthermore, the experimental spectra are in good agreement with electronic structure calculations performed with Dynamical Mean-Field Theory. The crystal field stabilization of the dxy orbital due to c-axis contraction is shown to be essential to explain the insulating phase. These results underscore the importance of multi-band physics, Coulomb interaction and Hund's coupling that together generate the Mott insulating state of Ca2RuO4. Detailed knowledge of the low-energy electronic structure is required to understand the Mott insulating phase of Ca2RuO4. Here, Sutter et al. provide directly the experimental band structure of the paramagnetic insulating phase of Ca2RuO4 and unveil the electronic origin of its Mott phase.
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Affiliation(s)
- D Sutter
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - C G Fatuzzo
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - S Moser
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - M Kim
- College de France, Paris Cedex 05 75231, France.,Centre de Physique Théorique, Ecole Polytechnique, CNRS, Univ Paris-Saclay, Palaiseau 91128, France
| | - R Fittipaldi
- CNR-SPIN, Fisciano, Salerno I-84084, Italy.,Dipartimento di Fisica 'E.R. Caianiello', Università di Salerno, Fisciano, Salerno I-84084, Italy
| | - A Vecchione
- CNR-SPIN, Fisciano, Salerno I-84084, Italy.,Dipartimento di Fisica 'E.R. Caianiello', Università di Salerno, Fisciano, Salerno I-84084, Italy
| | - V Granata
- CNR-SPIN, Fisciano, Salerno I-84084, Italy.,Dipartimento di Fisica 'E.R. Caianiello', Università di Salerno, Fisciano, Salerno I-84084, Italy
| | - Y Sassa
- Department of Physics and Astronomy, Uppsala University, Uppsala S-75121, Sweden
| | - F Cossalter
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - G Gatti
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - M Grioni
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - H M Rønnow
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI CH-5232, Switzerland
| | - C E Matt
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI CH-5232, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI CH-5232, Switzerland
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - T-R Chang
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.,Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - H-T Jeng
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.,Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - C Jozwiak
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - A Bostwick
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - E Rotenberg
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - A Georges
- College de France, Paris Cedex 05 75231, France.,Centre de Physique Théorique, Ecole Polytechnique, CNRS, Univ Paris-Saclay, Palaiseau 91128, France.,Department of Quantum Matter Physics, University of Geneva, Geneva 4 1211, Switzerland
| | - T Neupert
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - J Chang
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
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44
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Acharya S, Laad MS, Dey D, Maitra T, Taraphder A. First-Principles Correlated Approach to the Normal State of Strontium Ruthenate. Sci Rep 2017; 7:43033. [PMID: 28220879 PMCID: PMC5318872 DOI: 10.1038/srep43033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 01/17/2017] [Indexed: 11/12/2022] Open
Abstract
The interplay between multiple bands, sizable multi-band electronic correlations and strong spin-orbit coupling may conspire in selecting a rather unusual unconventional pairing symmetry in layered Sr2RuO4. This mandates a detailed revisit of the normal state and, in particular, the T-dependent incoherence-coherence crossover. Using a modern first-principles correlated view, we study this issue in the actual structure of Sr2RuO4 and present a unified and quantitative description of a range of unusual physical responses in the normal state. Armed with these, we propose that a new and important element, that of dominant multi-orbital charge fluctuations in a Hund's metal, may be a primary pair glue for unconventional superconductivity. Thereby we establish a connection between the normal state responses and superconductivity in this system.
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Affiliation(s)
- S. Acharya
- Department of Physics, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India
- Physics department, Kings College London, WC2R 2LS, UK
| | - M. S. Laad
- Institute of Mathematical Sciences, Taramani, Chennai 600113, India
- Max-Planck Inst. fuer Physik Komplexer Systeme, 38 Noethnitzer Strasse, 01187 Dresden, Germany
| | - Dibyendu Dey
- Department of Physics, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India
| | - T. Maitra
- Department of Physics, Indian Institute of Technology, Roorkee, Roorkee 247667, India
| | - A. Taraphder
- Department of Physics, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India
- Centre for Theoretical Studies, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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45
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Steppke A, Zhao L, Barber ME, Scaffidi T, Jerzembeck F, Rosner H, Gibbs AS, Maeno Y, Simon SH, Mackenzie AP, Hicks CW. Strong peak in
T
c
of Sr
2
RuO
4
under uniaxial pressure. Science 2017; 355:355/6321/eaaf9398. [DOI: 10.1126/science.aaf9398] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 11/18/2016] [Indexed: 11/02/2022]
Affiliation(s)
- Alexander Steppke
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, U.K
| | - Lishan Zhao
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, U.K
| | - Mark E. Barber
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, U.K
| | - Thomas Scaffidi
- Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, U.K
| | - Fabian Jerzembeck
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - Helge Rosner
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - Alexandra S. Gibbs
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, U.K
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 OQX, U.K
| | - Yoshiteru Maeno
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Steven H. Simon
- Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, U.K
| | - Andrew P. Mackenzie
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, U.K
| | - Clifford W. Hicks
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
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46
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Kondo T, Ochi M, Nakayama M, Taniguchi H, Akebi S, Kuroda K, Arita M, Sakai S, Namatame H, Taniguchi M, Maeno Y, Arita R, Shin S. Orbital-Dependent Band Narrowing Revealed in an Extremely Correlated Hund's Metal Emerging on the Topmost Layer of Sr_{2}RuO_{4}. PHYSICAL REVIEW LETTERS 2016; 117:247001. [PMID: 28009182 DOI: 10.1103/physrevlett.117.247001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Indexed: 06/06/2023]
Abstract
We use a surface-selective angle-resolved photoemission spectroscopy and unveil the electronic nature on the topmost layer of Sr_{2}RuO_{4} crystal, consisting of slightly rotated RuO_{6} octahedrons. The γ band derived from the 4d_{xy} orbital is found to be about three times narrower than that for the bulk. This strongly contrasts with a subtle variation seen in the α and β bands derived from the one-dimensional 4d_{xz/yz}. This anomaly is reproduced by the dynamical mean-field theory calculations, introducing not only the on-site Hubbard interaction but also the significant Hund's coupling. We detect a coherence-to-incoherence crossover theoretically predicted for Hund's metals, which has been recognized only recently. The crossover temperature in the surface is about half that of the bulk, indicating that the naturally generated monolayer of reconstructed Sr_{2}RuO_{4} is extremely correlated and well isolated from the underlying crystal.
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Affiliation(s)
- Takeshi Kondo
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - M Ochi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - M Nakayama
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - H Taniguchi
- Department of Materials Science and Engineering, Iwate University, Morioka 020-8551, Japan
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - S Akebi
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - K Kuroda
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - M Arita
- Hiroshima Synchrotron Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
| | - S Sakai
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - H Namatame
- Hiroshima Synchrotron Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
| | - M Taniguchi
- Hiroshima Synchrotron Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Y Maeno
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - R Arita
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
| | - S Shin
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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47
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Jang SW, Sakakibara H, Kino H, Kotani T, Kuroki K, Han MJ. Direct theoretical evidence for weaker correlations in electron-doped and Hg-based hole-doped cuprates. Sci Rep 2016; 6:33397. [PMID: 27633802 PMCID: PMC5025755 DOI: 10.1038/srep33397] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 08/26/2016] [Indexed: 11/24/2022] Open
Abstract
Many important questions for high-Tc cuprates are closely related to the insulating nature of parent compounds. While there has been intensive discussion on this issue, all arguments rely strongly on, or are closely related to, the correlation strength of the materials. Clear understanding has been seriously hampered by the absence of a direct measure of this interaction, traditionally denoted by U. Here, we report a first-principles estimation of U for several different types of cuprates. The U values clearly increase as a function of the inverse bond distance between apical oxygen and copper. Our results show that the electron-doped cuprates are less correlated than their hole-doped counterparts, which supports the Slater picture rather than the Mott picture. Further, the U values significantly vary even among the hole-doped families. The correlation strengths of the Hg-cuprates are noticeably weaker than that of La2CuO4. Our results suggest that the strong correlation enough to induce Mott gap may not be a prerequisite for the high-Tc superconductivity.
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Affiliation(s)
- Seung Woo Jang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Hirofumi Sakakibara
- Department of Applied Mathematics and Physics, Tottori University, Tottori 680-8552, Japan
- Computational Condensed Matter Physics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Hiori Kino
- National Institute for Materials Science, Sengen 1-2-1, Tsukuba, Ibaraki 305-0047, Japan
| | - Takao Kotani
- Department of Applied Mathematics and Physics, Tottori University, Tottori 680-8552, Japan
| | - Kazuhiko Kuroki
- Department of Physics, Osaka University, Machikaneyama-Cho, Toyonaka, Osaka 560-0043, Japan
| | - Myung Joon Han
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
- KAIST Institute for the NanoCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
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48
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Mravlje J, Georges A. Thermopower and Entropy: Lessons from Sr_{2}RuO_{4}. PHYSICAL REVIEW LETTERS 2016; 117:036401. [PMID: 27472124 DOI: 10.1103/physrevlett.117.036401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Indexed: 06/06/2023]
Abstract
We calculate the in-plane Seebeck coefficient of Sr_{2}RuO_{4} within a framework combining electronic structure and dynamical mean-field theory. We show that its temperature dependence can be interpreted using entropic considerations based on the Kelvin formula and that it provides a meaningful probe of the crossover out of the Fermi liquid regime into an incoherent metal. This crossover proceeds in two stages: The entropy of spin degrees of freedom is released around room temperature, while orbital degrees of freedom remain quenched up to much higher temperatures. This is confirmed by a direct calculation of the corresponding susceptibilities and is a hallmark of "Hund's metals." We also calculate the c-axis thermopower and predict that it exceeds substantially the in-plane one at high temperature, a peculiar behavior which originates from an interlayer "hole-filtering" mechanism.
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Affiliation(s)
| | - Antoine Georges
- Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
- Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France
- DQMP, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Genève, Switzerland
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49
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Deng X, Haule K, Kotliar G. Transport Properties of Metallic Ruthenates: A DFT+DMFT Investigation. PHYSICAL REVIEW LETTERS 2016; 116:256401. [PMID: 27391734 DOI: 10.1103/physrevlett.116.256401] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 06/06/2023]
Abstract
We present a systematical theoretical study on the transport properties of an archetypal family of Hund's metals, Sr_{2}RuO_{4}, Sr_{3}Ru_{2}O_{7}, SrRuO_{3}, and CaRuO_{3}, within the combination of first principles density functional theory and dynamical mean field theory. The agreement between theory and experiments for optical conductivity and resistivity is good, which indicates that electron-electron scattering dominates the transport of ruthenates. We demonstrate that in the single-site dynamical mean field approach the transport properties of Hund's metals fall into the scenario of "resilient quasiparticles." We explain why the single layered compound Sr_{2}RuO_{4} has a relative weak correlation with respect to its siblings, which corroborates its good metallicity.
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Affiliation(s)
- Xiaoyu Deng
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Kristjan Haule
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Gabriel Kotliar
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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50
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Burganov B, Adamo C, Mulder A, Uchida M, King PDC, Harter JW, Shai DE, Gibbs AS, Mackenzie AP, Uecker R, Bruetzam M, Beasley MR, Fennie CJ, Schlom DG, Shen KM. Strain Control of Fermiology and Many-Body Interactions in Two-Dimensional Ruthenates. PHYSICAL REVIEW LETTERS 2016; 116:197003. [PMID: 27232037 DOI: 10.1103/physrevlett.116.197003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Indexed: 06/05/2023]
Abstract
Here we demonstrate how the Fermi surface topology and quantum many-body interactions can be manipulated via epitaxial strain in the spin-triplet superconductor Sr_{2}RuO_{4} and its isoelectronic counterpart Ba_{2}RuO_{4} using oxide molecular beam epitaxy, in situ angle-resolved photoemission spectroscopy, and transport measurements. Near the topological transition of the γ Fermi surface sheet, we observe clear signatures of critical fluctuations, while the quasiparticle mass enhancement is found to increase rapidly and monotonically with increasing Ru-O bond distance. Our work demonstrates the possibilities for using epitaxial strain as a disorder-free means of manipulating emergent properties, many-body interactions, and potentially the superconductivity in correlated materials.
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Affiliation(s)
- B Burganov
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - C Adamo
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - A Mulder
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
| | - M Uchida
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - P D C King
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
- School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, United Kingdom
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA
| | - J W Harter
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - D E Shai
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - A S Gibbs
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - A P Mackenzie
- School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, United Kingdom
- Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - R Uecker
- Leibniz Institute for Crystal Growth, D-12489 Berlin, Germany
| | - M Bruetzam
- Leibniz Institute for Crystal Growth, D-12489 Berlin, Germany
| | - M R Beasley
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - C J Fennie
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA
| | - D G Schlom
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA
| | - K M Shen
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA
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