1
|
Khim S, Landaeta JF, Banda J, Bannor N, Brando M, Brydon PMR, Hafner D, Küchler R, Cardoso-Gil R, Stockert U, Mackenzie AP, Agterberg DF, Geibel C, Hassinger E. Field-induced transition within the superconducting state of CeRh 2As 2. Science 2021; 373:1012-1016. [PMID: 34446602 DOI: 10.1126/science.abe7518] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 07/23/2021] [Indexed: 11/02/2022]
Abstract
Materials with multiple superconducting phases are rare. Here, we report the discovery of two-phase unconventional superconductivity in CeRh2As2 Using thermodynamic probes, we establish that the superconducting critical field of its high-field phase is as high as 14 tesla, even though the transition temperature is only 0.26 kelvin. Furthermore, a transition between two different superconducting phases is observed in a c axis magnetic field. Local inversion-symmetry breaking at the cerium sites enables Rashba spin-orbit coupling alternating between the cerium sublayers. The staggered Rashba coupling introduces a layer degree of freedom to which the field-induced transition and high critical field seen in experiment are likely related.
Collapse
Affiliation(s)
- S Khim
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA. .,Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - J F Landaeta
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - J Banda
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - N Bannor
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - M Brando
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - P M R Brydon
- Department of Physics and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, Dunedin 9054, New Zealand.,Department of Physics and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, Dunedin 9054, New Zealand
| | - D Hafner
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - R Küchler
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - R Cardoso-Gil
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.,Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - U Stockert
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.,Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - A P Mackenzie
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.,Department of Physics and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, Dunedin 9054, New Zealand.,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, UK
| | - D F Agterberg
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.,Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - C Geibel
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - E Hassinger
- Physik Department, Technische Universität München, 85748 Garching, Germany. .,Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.,Physik Department, Technische Universität München, 85748 Garching, Germany
| |
Collapse
|
2
|
Sunko V, Mazzola F, Kitamura S, Khim S, Kushwaha P, Clark OJ, Watson MD, Marković I, Biswas D, Pourovskii L, Kim TK, Lee TL, Thakur PK, Rosner H, Georges A, Moessner R, Oka T, Mackenzie AP, King PDC. Probing spin correlations using angle-resolved photoemission in a coupled metallic/Mott insulator system. Sci Adv 2020; 6:eaaz0611. [PMID: 32128385 PMCID: PMC7032925 DOI: 10.1126/sciadv.aaz0611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/29/2019] [Indexed: 06/10/2023]
Abstract
A nearly free electron metal and a Mott insulating state can be thought of as opposite ends of the spectrum of possibilities for the motion of electrons in a solid. Understanding their interaction lies at the heart of the correlated electron problem. In the magnetic oxide metal PdCrO2, nearly free and Mott-localized electrons exist in alternating layers, forming natural heterostructures. Using angle-resolved photoemission spectroscopy, quantitatively supported by a strong coupling analysis, we show that the coupling between these layers leads to an "intertwined" excitation that is a convolution of the charge spectrum of the metallic layer and the spin susceptibility of the Mott layer. Our findings establish PdCrO2 as a model system in which to probe Kondo lattice physics and also open new routes to use the a priori nonmagnetic probe of photoemission to gain insights into the spin susceptibility of correlated electron materials.
Collapse
Affiliation(s)
- V. Sunko
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - F. Mazzola
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - S. Kitamura
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - S. Khim
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P. Kushwaha
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - O. J. Clark
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - M. D. Watson
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - I. Marković
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - D. Biswas
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - L. Pourovskii
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
- Institut de Physique, Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - T. K. Kim
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - T.-L. Lee
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - P. K. Thakur
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - H. Rosner
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - A. Georges
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
- Institut de Physique, Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
- Center for Computational Quantum Physics, Flatiron Institute, New York, NY 10010, USA
- DQMP, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Genève, Switzerland
| | - R. Moessner
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - T. Oka
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - A. P. Mackenzie
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P. D. C. King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| |
Collapse
|
3
|
Sunko V, Rosner H, Kushwaha P, Khim S, Mazzola F, Bawden L, Clark OJ, Riley JM, Kasinathan D, Haverkort MW, Kim TK, Hoesch M, Fujii J, Vobornik I, Mackenzie AP, King PDC. Maximal Rashba-like spin splitting via kinetic-energy-coupled inversion-symmetry breaking. Nature 2018; 549:492-496. [PMID: 28959958 DOI: 10.1038/nature23898] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/26/2017] [Indexed: 11/09/2022]
Abstract
Engineering and enhancing the breaking of inversion symmetry in solids-that is, allowing electrons to differentiate between 'up' and 'down'-is a key goal in condensed-matter physics and materials science because it can be used to stabilize states that are of fundamental interest and also have potential practical applications. Examples include improved ferroelectrics for memory devices and materials that host Majorana zero modes for quantum computing. Although inversion symmetry is naturally broken in several crystalline environments, such as at surfaces and interfaces, maximizing the influence of this effect on the electronic states of interest remains a challenge. Here we present a mechanism for realizing a much larger coupling of inversion-symmetry breaking to itinerant surface electrons than is typically achieved. The key element is a pronounced asymmetry of surface hopping energies-that is, a kinetic-energy-coupled inversion-symmetry breaking, the energy scale of which is a substantial fraction of the bandwidth. Using spin- and angle-resolved photoemission spectroscopy, we demonstrate that such a strong inversion-symmetry breaking, when combined with spin-orbit interactions, can mediate Rashba-like spin splittings that are much larger than would typically be expected. The energy scale of the inversion-symmetry breaking that we achieve is so large that the spin splitting in the CoO2- and RhO2-derived surface states of delafossite oxides becomes controlled by the full atomic spin-orbit coupling of the 3d and 4d transition metals, resulting in some of the largest known Rashba-like spin splittings. The core structural building blocks that facilitate the bandwidth-scaled inversion-symmetry breaking are common to numerous materials. Our findings therefore provide opportunities for creating spin-textured states and suggest routes to interfacial control of inversion-symmetry breaking in designer heterostructures of oxides and other material classes.
Collapse
Affiliation(s)
- Veronika Sunko
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - H Rosner
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P Kushwaha
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - S Khim
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - F Mazzola
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - L Bawden
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - O J Clark
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - J M Riley
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - D Kasinathan
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - M W Haverkort
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120 Heidelberg, Germany
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - J Fujii
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, Km 163.5, 34149 Trieste, Italy
| | - I Vobornik
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, Km 163.5, 34149 Trieste, Italy
| | - A P Mackenzie
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| |
Collapse
|
4
|
Bhoi D, Khim S, Nam W, Lee BS, Kim C, Jeon BG, Min BH, Park S, Kim KH. Interplay of charge density wave and multiband superconductivity in 2H-PdxTaSe2. Sci Rep 2016; 6:24068. [PMID: 27045426 PMCID: PMC4820724 DOI: 10.1038/srep24068] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 03/17/2016] [Indexed: 12/03/2022] Open
Abstract
2H-TaSe2 has been one of unique transition metal dichalcogenides exhibiting several phase transitions due to a delicate balance among competing electronic ground states. An unusual metallic state at high-T is sequentially followed by an incommensurate charge density wave (ICDW) state at ≈122 K and a commensurate charge density wave (CCDW) state at ≈90 K, and superconductivity at TC ~ 0.14 K. Upon systematic intercalation of Pd ions into TaSe2, we find that CCDW order is destabilized more rapidly than ICDW to indicate a hidden quantum phase transition point at x ~ 0.09-0.10. Moreover, TC shows a dramatic enhancement up to 3.3 K at x = 0.08, ~24 times of TC in 2H-TaSe2, in proportional to the density of states N(EF). Investigations of upper critical fields Hc2 in single crystals reveal evidences of multiband superconductivity as temperature-dependent anisotropy factor γH = , quasi-linear increase of , and an upward, positive-curvature in near TC. Furthermore, analysis of temperature-dependent electronic specific heat corroborates the presence of multiple superconducting gaps. Based on above findings and electronic phase diagram vs x, we propose that the increase of N(EF) and effective electron-phonon coupling in the vicinity of CDW quantum phase transition should be a key to the large enhancement of TC in PdxTaSe2.
Collapse
Affiliation(s)
- D. Bhoi
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - S. Khim
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - W. Nam
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - B. S. Lee
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - Chanhee Kim
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - B.-G. Jeon
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - B. H. Min
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - S. Park
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| | - Kee Hoon Kim
- Center for Novel States of Complex Materials Research and Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Republic of Korea
| |
Collapse
|