1
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Arai Y, Kuroda K, Nomoto T, Tin ZH, Sakuragi S, Bareille C, Akebi S, Kurokawa K, Kinoshita Y, Zhang WL, Shin S, Tokunaga M, Kitazawa H, Haga Y, Suzuki HS, Miyasaka S, Tajima S, Iwasa K, Arita R, Kondo T. Multipole polaron in the devil's staircase of CeSb. Nat Mater 2022; 21:410-415. [PMID: 35145257 DOI: 10.1038/s41563-021-01188-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
Rare-earth intermetallic compounds exhibit rich phenomena induced by the interplay between localized f orbitals and conduction electrons. However, since the energy scale of the crystal-electric-field splitting is only a few millielectronvolts, the nature of the mobile electrons accompanied by collective crystal-electric-field excitations has not been unveiled. Here, we examine the low-energy electronic structures of CeSb through the anomalous magnetostructural transitions below the Néel temperature, ~17 K, termed the 'devil's staircase', using laser angle-resolved photoemission, Raman and neutron scattering spectroscopies. We report another type of electron-boson coupling between mobile electrons and quadrupole crystal-electric-field excitations of the 4f orbitals, which renormalizes the Sb 5p band prominently, yielding a kink at a very low energy (~7 meV). This coupling strength is strong and exhibits anomalous step-like enhancement during the devil's staircase transition, unveiling a new type of quasiparticle, named the 'multipole polaron', comprising a mobile electron dressed with a cloud of the quadrupole crystal-electric-field polarization.
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Affiliation(s)
- Y Arai
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Kenta Kuroda
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan.
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashihiroshima, Japan.
| | - T Nomoto
- Department of Applied Physics, The University of Tokyo, Tokyo, Japan
| | - Z H Tin
- Department of Physics, Osaka University, Toyonaka, Japan
| | - S Sakuragi
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - C Bareille
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - S Akebi
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - K Kurokawa
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Y Kinoshita
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - W-L Zhang
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
- Department of Engineering and Applied Sciences, Sophia University, Tokyo, Japan
| | - S Shin
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
- Office of University Professor, The University of Tokyo, Kashiwa, Japan
| | - M Tokunaga
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
- Trans-scale Quantum Science Institute, The University of Tokyo, Tokyo, Japan
| | - H Kitazawa
- National Institute for Materials Science, Tsukuba, Japan
| | - Y Haga
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Japan
| | - H S Suzuki
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - S Miyasaka
- Department of Physics, Osaka University, Toyonaka, Japan
| | - S Tajima
- Department of Physics, Osaka University, Toyonaka, Japan
| | - K Iwasa
- Frontier Research Center for Applied Atomic Sciences and Institute of Quantum Beam Science, Ibaraki University, Tokai, Japan
| | - R Arita
- Department of Applied Physics, The University of Tokyo, Tokyo, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - Takeshi Kondo
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
- Trans-scale Quantum Science Institute, The University of Tokyo, Tokyo, Japan
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2
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Shimojima T, Motoyui Y, Taniuchi T, Bareille C, Onari S, Kontani H, Nakajima M, Kasahara S, Shibauchi T, Matsuda Y, Shin S. Discovery of mesoscopic nematicity wave in iron-based superconductors. Science 2021; 373:1122-1125. [PMID: 34516833 DOI: 10.1126/science.abd6701] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- T Shimojima
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Y Motoyui
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan
| | - T Taniuchi
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan.,Material Innovation Research Center (MIRC), The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - C Bareille
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan.,Material Innovation Research Center (MIRC), The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - S Onari
- Department of Physics, Nagoya University, Furo-cho, Nagoya 464-8602, Japan
| | - H Kontani
- Department of Physics, Nagoya University, Furo-cho, Nagoya 464-8602, Japan
| | - M Nakajima
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - S Kasahara
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - T Shibauchi
- Department of Advanced Materials Science, The University of Tokyo, Kashiwa 277-8561, Japan
| | - Y Matsuda
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - S Shin
- Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa 277-8581, Japan.,Material Innovation Research Center (MIRC), The University of Tokyo, Kashiwa, Chiba 277-8561, Japan.,Office of University Professor, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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3
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Noguchi R, Takahashi T, Kuroda K, Ochi M, Shirasawa T, Sakano M, Bareille C, Nakayama M, Watson MD, Yaji K, Harasawa A, Iwasawa H, Dudin P, Kim TK, Hoesch M, Kandyba V, Giampietri A, Barinov A, Shin S, Arita R, Sasagawa T, Kondo T. Publisher Correction: A weak topological insulator state in quasi-one-dimensional bismuth iodide. Nature 2020; 584:E4. [PMID: 32690939 DOI: 10.1038/s41586-020-2392-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Ryo Noguchi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - T Takahashi
- Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama, Japan
| | - K Kuroda
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - M Ochi
- Department of Physics, Osaka University, Toyonaka, Japan
| | - T Shirasawa
- National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - M Sakano
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan.,Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo, Japan
| | - C Bareille
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - M Nakayama
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - M D Watson
- Diamond Light Source, Harwell Campus, Didcot, UK
| | - K Yaji
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - A Harasawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - H Iwasawa
- Diamond Light Source, Harwell Campus, Didcot, UK.,Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan
| | - P Dudin
- Diamond Light Source, Harwell Campus, Didcot, UK
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot, UK
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot, UK.,DESY Photon Science, Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - V Kandyba
- Elettra - Sincrotrone Trieste, Basovizza, Italy
| | | | - A Barinov
- Elettra - Sincrotrone Trieste, Basovizza, Italy
| | - S Shin
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - R Arita
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - T Sasagawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama, Japan.
| | - Takeshi Kondo
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan.
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4
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Kuroda K, Arai Y, Rezaei N, Kunisada S, Sakuragi S, Alaei M, Kinoshita Y, Bareille C, Noguchi R, Nakayama M, Akebi S, Sakano M, Kawaguchi K, Arita M, Ideta S, Tanaka K, Kitazawa H, Okazaki K, Tokunaga M, Haga Y, Shin S, Suzuki HS, Arita R, Kondo T. Devil's staircase transition of the electronic structures in CeSb. Nat Commun 2020; 11:2888. [PMID: 32514054 PMCID: PMC7280508 DOI: 10.1038/s41467-020-16707-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 05/15/2020] [Indexed: 12/02/2022] Open
Abstract
Solids with competing interactions often undergo complex phase transitions with a variety of long-periodic modulations. Among such transition, devil's staircase is the most complex phenomenon, and for it, CeSb is the most famous material, where a number of the distinct phases with long-periodic magnetostructures sequentially appear below the Néel temperature. An evolution of the low-energy electronic structure going through the devil's staircase is of special interest, which has, however, been elusive so far despite 40 years of intense research. Here, we use bulk-sensitive angle-resolved photoemission spectroscopy and reveal the devil's staircase transition of the electronic structures. The magnetic reconstruction dramatically alters the band dispersions at each transition. Moreover, we find that the well-defined band picture largely collapses around the Fermi energy under the long-periodic modulation of the transitional phase, while it recovers at the transition into the lowest-temperature ground state. Our data provide the first direct evidence for a significant reorganization of the electronic structures and spectral functions occurring during the devil's staircase.
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Affiliation(s)
- Kenta Kuroda
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan.
| | - Y Arai
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - N Rezaei
- Department of Physics, Isfahan University of Technology, 84156-83111, Isfahan, Iran
| | - S Kunisada
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - S Sakuragi
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - M Alaei
- Department of Physics, Isfahan University of Technology, 84156-83111, Isfahan, Iran
| | - Y Kinoshita
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - C Bareille
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - R Noguchi
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - M Nakayama
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - S Akebi
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - M Sakano
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - K Kawaguchi
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - M Arita
- Hiroshima Synchrotron Center, Hiroshima University, Higashi-Hiroshima, 739-0046, Japan
| | - S Ideta
- UVSOR Facility, Institute for Molecular Science, Okazaki, 444-8585, Japan
| | - K Tanaka
- UVSOR Facility, Institute for Molecular Science, Okazaki, 444-8585, Japan
| | - H Kitazawa
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047, Japan
| | - K Okazaki
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - M Tokunaga
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Y Haga
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan
| | - S Shin
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - H S Suzuki
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - R Arita
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Takeshi Kondo
- ISSP, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
- Trans-scale Quantum Science Institute, University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
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5
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Noguchi R, Takahashi T, Kuroda K, Ochi M, Shirasawa T, Sakano M, Bareille C, Nakayama M, Watson MD, Yaji K, Harasawa A, Iwasawa H, Dudin P, Kim TK, Hoesch M, Kandyba V, Giampietri A, Barinov A, Shin S, Arita R, Sasagawa T, Kondo T. A weak topological insulator state in quasi-one-dimensional bismuth iodide. Nature 2019; 566:518-522. [DOI: 10.1038/s41586-019-0927-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 11/24/2018] [Indexed: 11/09/2022]
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6
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Kuroda K, Tomita T, Suzuki MT, Bareille C, Nugroho AA, Goswami P, Ochi M, Ikhlas M, Nakayama M, Akebi S, Noguchi R, Ishii R, Inami N, Ono K, Kumigashira H, Varykhalov A, Muro T, Koretsune T, Arita R, Shin S, Kondo T, Nakatsuji S. Evidence for magnetic Weyl fermions in a correlated metal. Nat Mater 2017; 16:1090-1095. [PMID: 28967918 DOI: 10.1038/nmat4987] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 08/21/2017] [Indexed: 06/07/2023]
Abstract
Weyl fermions have been observed as three-dimensional, gapless topological excitations in weakly correlated, inversion-symmetry-breaking semimetals. However, their realization in spontaneously time-reversal-symmetry-breaking phases of strongly correlated materials has so far remained hypothetical. Here, we report experimental evidence for magnetic Weyl fermions in Mn3Sn, a non-collinear antiferromagnet that exhibits a large anomalous Hall effect, even at room temperature. Detailed comparison between angle-resolved photoemission spectroscopy (ARPES) measurements and density functional theory (DFT) calculations reveals significant bandwidth renormalization and damping effects due to the strong correlation among Mn 3d electrons. Magnetotransport measurements provide strong evidence for the chiral anomaly of Weyl fermions-namely, the emergence of positive magnetoconductance only in the presence of parallel electric and magnetic fields. Since weak magnetic fields (approximately 10 mT) are adequate to control the distribution of Weyl points and the large fictitious fields (equivalent to approximately a few hundred T) produced by them in momentum space, our discovery lays the foundation for a new field of science and technology involving the magnetic Weyl excitations of strongly correlated electron systems such as Mn3Sn.
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Affiliation(s)
- K Kuroda
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - T Tomita
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - M-T Suzuki
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - C Bareille
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - A A Nugroho
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
- Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, 40132 Bandung, Indonesia
| | - P Goswami
- Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742- 4111, USA
- Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, Illinois 60208, USA
| | - M Ochi
- Department of Physics, Osaka University, Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan
| | - M Ikhlas
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - M Nakayama
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - S Akebi
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - R Noguchi
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - R Ishii
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - N Inami
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - K Ono
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Kumigashira
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - A Varykhalov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - T Muro
- Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - T Koretsune
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - R Arita
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Shin
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - Takeshi Kondo
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - S Nakatsuji
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
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7
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Nakayama M, Kondo T, Tian Z, Ishikawa JJ, Halim M, Bareille C, Malaeb W, Kuroda K, Tomita T, Ideta S, Tanaka K, Matsunami M, Kimura S, Inami N, Ono K, Kumigashira H, Balents L, Nakatsuji S, Shin S. Slater to Mott Crossover in the Metal to Insulator Transition of Nd_{2}Ir_{2}O_{7}. Phys Rev Lett 2016; 117:056403. [PMID: 27517783 DOI: 10.1103/physrevlett.117.056403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Indexed: 06/06/2023]
Abstract
We present an angle-resolved photoemission study of the electronic structure of the three-dimensional pyrochlore iridate Nd_{2}Ir_{2}O_{7} through its magnetic metal-insulator transition. Our data reveal that metallic Nd_{2}Ir_{2}O_{7} has a quadratic band, touching the Fermi level at the Γ point, similar to that of Pr_{2}Ir_{2}O_{7}. The Fermi node state is, therefore, a common feature of the metallic phase of the pyrochlore iridates. Upon cooling below the transition temperature, this compound exhibits a gap opening with an energy shift of quasiparticle peaks like a band gap insulator. The quasiparticle peaks are strongly suppressed, however, with further decrease of temperature, and eventually vanish at the lowest temperature, leaving a nondispersive flat band lacking long-lived electrons. We thereby identify a remarkable crossover from Slater to Mott insulators with decreasing temperature. These observations explain the puzzling absence of Weyl points in this material, despite its proximity to the zero temperature metal-insulator transition.
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Affiliation(s)
- M Nakayama
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Takeshi Kondo
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Z Tian
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - J J Ishikawa
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - M Halim
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - C Bareille
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - W Malaeb
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- Physics Department, Faculty of Science, Beirut Arab University, Beirut 11-5020, Lebanon
| | - K Kuroda
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - T Tomita
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - S Ideta
- UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
| | - K Tanaka
- UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
| | - M Matsunami
- Toyota Technological Institute, Nagoya 468-8511, Japan
| | - S Kimura
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - N Inami
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - K Ono
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Kumigashira
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - L Balents
- Kavli Institute for Theoretical Physics, Santa Barbara, California 93106, USA
| | - S Nakatsuji
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - S Shin
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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8
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Santander-Syro AF, Fortuna F, Bareille C, Rödel TC, Landolt G, Plumb NC, Dil JH, Radović M. Giant spin splitting of the two-dimensional electron gas at the surface of SrTiO3. Nat Mater 2014; 13:1085-1090. [PMID: 25306421 DOI: 10.1038/nmat4107] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 09/05/2014] [Indexed: 06/04/2023]
Abstract
Two-dimensional electron gases (2DEGs) forming at the interfaces of transition metal oxides exhibit a range of properties, including tunable insulator-superconductor-metal transitions, large magnetoresistance, coexisting ferromagnetism and superconductivity, and a spin splitting of a few meV (refs 10, 11). Strontium titanate (SrTiO3), the cornerstone of such oxide-based electronics, is a transparent, non-magnetic, wide-bandgap insulator in the bulk, and has recently been found to host a surface 2DEG (refs 12-15). The most strongly confined carriers within this 2DEG comprise two subbands, separated by an energy gap of 90 meV and forming concentric circular Fermi surfaces. Using spin- and angle-resolved photoemission spectroscopy (SARPES), we show that the electron spins in these subbands have opposite chiralities. Although the Rashba effect might be expected to give rise to such spin textures, the giant splitting of almost 100 meV at the Fermi level is far larger than anticipated. Moreover, in contrast to a simple Rashba system, the spin-polarized subbands are non-degenerate at the Brillouin zone centre. This degeneracy can be lifted by time-reversal symmetry breaking, implying the possible existence of magnetic order. These results show that confined electronic states at oxide surfaces can be endowed with novel, non-trivial properties that are both theoretically challenging to anticipate and promising for technological applications.
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Affiliation(s)
- A F Santander-Syro
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France
| | - F Fortuna
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France
| | - C Bareille
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France
| | - T C Rödel
- 1] CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France [2] Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - G Landolt
- 1] Physik-Institut, Universität Zürich, Winterthurerstrasse 190 8057 Zürich, Switzerland [2] Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - J H Dil
- 1] Physik-Institut, Universität Zürich, Winterthurerstrasse 190 8057 Zürich, Switzerland [2] Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland [3] Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - M Radović
- 1] Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland [2] Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland [3] SwissFEL, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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Bareille C, Fortuna F, Rödel TC, Bertran F, Gabay M, Cubelos OH, Taleb-Ibrahimi A, Le Fèvre P, Bibes M, Barthélémy A, Maroutian T, Lecoeur P, Rozenberg MJ, Santander-Syro AF. Two-dimensional electron gas with six-fold symmetry at the (111) surface of KTaO3. Sci Rep 2014; 4:3586. [PMID: 24394996 PMCID: PMC3882744 DOI: 10.1038/srep03586] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 12/03/2013] [Indexed: 11/09/2022] Open
Abstract
Two-dimensional electron gases (2DEGs) at transition-metal oxide (TMO) interfaces, and boundary states in topological insulators, are being intensively investigated. The former system harbors superconductivity, large magneto-resistance, and ferromagnetism. In the latter, honeycomb-lattice geometry plus bulk spin-orbit interactions lead to topologically protected spin-polarized bands. 2DEGs in TMOs with a honeycomb-like structure could yield new states of matter, but they had not been experimentally realized, yet. We successfully created a 2DEG at the (111) surface of KTaO3, a strong insulator with large spin-orbit coupling. Its confined states form a network of weakly-dispersing electronic gutters with 6-fold symmetry, a topology novel to all known oxide-based 2DEGs. If those pertain to just one Ta-(111) bilayer, model calculations predict that it can be a topological metal. Our findings demonstrate that completely new electronic states, with symmetries not realized in the bulk, can be tailored in oxide surfaces, promising for TMO-based devices.
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Affiliation(s)
- C Bareille
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France
| | - F Fortuna
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France
| | - T C Rödel
- 1] CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France [2] Universität Würzburg, Experimentelle Physik VII, Am Hubland, 97074 Würzburg, Germany
| | - F Bertran
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - M Gabay
- Laboratoire de Physique des Solides, Université Paris-Sud and CNRS, Bâtiment 510, 91405 Orsay, France
| | - O Hijano Cubelos
- Laboratoire de Physique des Solides, Université Paris-Sud and CNRS, Bâtiment 510, 91405 Orsay, France
| | - A Taleb-Ibrahimi
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - P Le Fèvre
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - M Bibes
- Unité Mixte de Physique CNRS/Thales, Campus de l'Ecole Polytechnique, 1 Av. A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - A Barthélémy
- Unité Mixte de Physique CNRS/Thales, Campus de l'Ecole Polytechnique, 1 Av. A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - T Maroutian
- Institut d'Electronique Fondamentale, Université Paris-Sud and CNRS, Bâtiment 220, 91405 Orsay, France
| | - P Lecoeur
- Institut d'Electronique Fondamentale, Université Paris-Sud and CNRS, Bâtiment 220, 91405 Orsay, France
| | - M J Rozenberg
- Laboratoire de Physique des Solides, Université Paris-Sud and CNRS, Bâtiment 510, 91405 Orsay, France
| | - A F Santander-Syro
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay cedex, France
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Boariu FL, Bareille C, Schwab H, Nuber A, Lejay P, Durakiewicz T, Reinert F, Santander-Syro AF. Momentum-resolved evolution of the Kondo lattice into "hidden order" in URu2Si2. Phys Rev Lett 2013; 110:156404. [PMID: 25167291 DOI: 10.1103/physrevlett.110.156404] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Indexed: 06/03/2023]
Abstract
We study, using high-resolution angle-resolved photoemission spectroscopy, the evolution of the electronic structure in URu2Si2 at the Γ, Z, and X high-symmetry points from the high-temperature Kondo-screened regime to the low-temperature hidden-order (HO) state. At all temperatures and symmetry points, we find structures resulting from the interaction between heavy and light bands related to the Kondo-lattice formation. At the X point, we directly measure a hybridization gap of 11 meV already open at temperatures above the ordered phase. Strikingly, we find that while the HO induces pronounced changes at Γ and Z, the hybridization gap at X does not change, indicating that the hidden-order parameter is anisotropic. Furthermore, at the Γ and Z points, we observe the opening of a gap in momentum in the HO state, and show that the associated electronic structure results from the hybridization of a light electron band with the Kondo-lattice bands characterizing the paramagnetic state.
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Affiliation(s)
- F L Boariu
- Lehrstuhl für Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - C Bareille
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay Cedex, France
| | - H Schwab
- Lehrstuhl für Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - A Nuber
- Lehrstuhl für Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - P Lejay
- Institut Néel, CNRS/UJF, B.P. 166, 38042 Grenoble Cedex 9, France
| | - T Durakiewicz
- MPA-CMMS, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA
| | - F Reinert
- Lehrstuhl für Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany and Karlsruher Institut für Technologie (KIT), Gemeinschaftslabor für Nanoanalythik, D-76021 Karlsruhe, Germany
| | - A F Santander-Syro
- CSNSM, Université Paris-Sud and CNRS/IN2P3, Bâtiments 104 et 108, 91405 Orsay Cedex, France
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