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Kurzhals P, Kremer G, Jaouen T, Nicholson CW, Heid R, Nagel P, Castellan JP, Ivanov A, Muntwiler M, Rumo M, Salzmann B, Strocov VN, Reznik D, Monney C, Weber F. Electron-momentum dependence of electron-phonon coupling underlies dramatic phonon renormalization in YNi 2B 2C. Nat Commun 2022; 13:228. [PMID: 35017477 PMCID: PMC8752669 DOI: 10.1038/s41467-021-27843-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/16/2021] [Indexed: 11/09/2022] Open
Abstract
Electron-phonon coupling, i.e., the scattering of lattice vibrations by electrons and vice versa, is ubiquitous in solids and can lead to emergent ground states such as superconductivity and charge-density wave order. A broad spectral phonon line shape is often interpreted as a marker of strong electron-phonon coupling associated with Fermi surface nesting, i.e., parallel sections of the Fermi surface connected by the phonon momentum. Alternatively broad phonons are known to arise from strong atomic lattice anharmonicity. Here, we show that strong phonon broadening can occur in the absence of both Fermi surface nesting and lattice anharmonicity, if electron-phonon coupling is strongly enhanced for specific values of electron-momentum, k. We use inelastic neutron scattering, soft x-ray angle-resolved photoemission spectroscopy measurements and ab-initio lattice dynamical and electronic band structure calculations to demonstrate this scenario in the highly anisotropic tetragonal electron-phonon superconductor YNi2B2C. This new scenario likely applies to a wide range of compounds.
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Affiliation(s)
- Philipp Kurzhals
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Geoffroy Kremer
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Thomas Jaouen
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000, Rennes, France
| | - Christopher W Nicholson
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Rolf Heid
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - Peter Nagel
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | - John-Paul Castellan
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
- Laboratoire Léon Brillouin (CEA-CNRS), CEA Saclay, F-91911, Gif-sur-Yvette, France
| | - Alexandre Ivanov
- Institut Laue-Langevin, 71 avenue des Martyrs CS 20156, 38042, Grenoble Cedex 9, France
| | - Matthias Muntwiler
- Paul Scherrer Institut, Swiss Light Source, 5232, Villigen PSI, Switzerland
| | - Maxime Rumo
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Bjoern Salzmann
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Vladimir N Strocov
- Paul Scherrer Institut, Swiss Light Source, 5232, Villigen PSI, Switzerland
| | - Dmitry Reznik
- Department of Physics, University of Colorado at Boulder, Boulder, CO, 80309, USA
- Center for Experiments on Quantum Materials, University of Colorado at Boulder, Boulder, CO, 80309, USA
| | - Claude Monney
- Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700, Fribourg, Switzerland
| | - Frank Weber
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany.
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Gundogdu S, Clancy JP, Xu G, Zhao Y, Dube PA, Karalar TC, Cho BK, Lynn JW, Ramazanoglu M. Magnetic order and competition with superconductivity in (Ho-Er)Ni 2B 2C. MATERIALS RESEARCH EXPRESS 2020; 7:10.1088/2053-1591/abc998. [PMID: 37719937 PMCID: PMC10502616 DOI: 10.1088/2053-1591/abc998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
The rare earth magnetic order in pure and doped H o ( 1 - x ) E r x N i 2 B 2 C (x = 0, 0.25, 0.50, 0.75, 1) single crystal samples was investigated using magnetization and neutron diffraction measurements. Superconducting quaternary borocarbides, R N i 2 B 2 C where R = Ho, Er , are magnetic intermetallic superconductors with the transition temperatures~10 K in which long range magnetic order develops in the same temperature range and competes with superconductivity. Depending on the rare earth composition the coupling between superconductivity and magnetism creates several phases, ranging from a near reentrant superconductor with a mixture of commensurate and incommensurate antiferromagnetism to an incommensurate antiferromagnetic spin modulation with a weak ferromagnetic component. All of these phases coexist with superconductivity. RKKY magnetic interactions are used to describe the magnetic orders in the pure compounds. However, the doping of Er on Ho sites which have two strong magnetic moments with two different easy directions creates new and complicated magnetic modulations with possible local disorder effects. One fascinating effect is the development of an induced magnetic state resembling the pure and doped R2CuO4 cuprate with R = Nd and Pr.
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Affiliation(s)
- Suleyman Gundogdu
- Physics Engineering Department, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
| | - J Patrick Clancy
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 Canada
| | - Guangyong Xu
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Yang Zhao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - Paul A Dube
- Brockhouse Institute for Materials Research, Hamilton, ON L8S 4M1, Canada
| | - Tufan C Karalar
- Electronics and Communication Engineering Department, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
| | - Beong Ki Cho
- Gwangju Institute of Science and Technology, GIST, Republic of Korea
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States of America
| | - M Ramazanoglu
- Physics Engineering Department, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
- Brockhouse Institute for Materials Research, Hamilton, ON L8S 4M1, Canada
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3
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Song Y, Wang W, Van Dyke JS, Pouse N, Ran S, Yazici D, Schneidewind A, Čermák P, Qiu Y, Maple MB, Morr DK, Dai P. Nature of the spin resonance mode in CeCoIn 5. COMMUNICATIONS PHYSICS 2020; 3:10.1038/s42005-020-0365-8. [PMID: 33655080 PMCID: PMC7919742 DOI: 10.1038/s42005-020-0365-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Spin-fluctuation-mediated unconventional superconductivity can emerge at the border of magnetism, featuring a superconducting order parameter that changes sign in momentum space. Detection of such a sign-change is experimentally challenging, since most probes are not phase-sensitive. The observation of a spin resonance mode (SRM) from inelastic neutron scattering is often seen as strong phase-sensitive evidence for a sign-changing superconducting order parameter, by assuming the SRM is a spin-excitonic bound state. Here we show that for the heavy fermion superconductor CeCoIn5, its SRM defies expectations for a spin-excitonic bound state, and is not a manifestation of sign-changing superconductivity. Instead, the SRM in CeCoIn5 likely arises from a reduction of damping to a magnon-like mode in the superconducting state, due to its proximity to magnetic quantum criticality. Our findings emphasize the need for more stringent tests of whether SRMs are spin-excitonic, when using their presence to evidence sign-changing superconductivity.
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Affiliation(s)
- Yu Song
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | - Weiyi Wang
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
| | - John S. Van Dyke
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Naveen Pouse
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sheng Ran
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, CA 92093, USA
| | - Duygu Yazici
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, CA 92093, USA
| | - A. Schneidewind
- Jülich Center for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at MLZ, D-85747 Garching, Germany
| | - Petr Čermák
- Jülich Center for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at MLZ, D-85747 Garching, Germany
- Present address: Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Praha, Czech Republic
| | - Y. Qiu
- NIST center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - M. B. Maple
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
- Center for Advanced Nanoscience, University of California, San Diego, La Jolla, CA 92093, USA
| | - Dirk K. Morr
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Pengcheng Dai
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
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Smolyaninova VN, Lynn JW, Butch NP, Chen-Mayer H, Prestigiacomo JC, Osofsky MS, Smolyaninov II. Observation of plasmon-phonons in a metamaterial superconductor using inelastic neutron scattering. PHYSICAL REVIEW. B 2019; 100:10.1103/physrevb.100.024515. [PMID: 38845604 PMCID: PMC11155593 DOI: 10.1103/physrevb.100.024515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
A metamaterial approach is capable of drastically increasing the critical temperature,T c , of composite metal-dielectric superconductors as demonstrated by the tripling ofT c that was observed in bulk Al-Al2O3 coreshell metamaterials. A theoretical model based on the Maxwell-Garnett approximation provides a microscopic explanation of this effect in terms of electron-electron pairing mediated by a hybrid plasmon-phonon excitation. We report an observation of this excitation in Al-Al2O3 core-shell metamaterials using inelastic neutron scattering. This result provides support for this mechanism of superconductivity in metamaterials.
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Affiliation(s)
- Vera N Smolyaninova
- Department of Physics Astronomy and Geosciences, Towson University, 8000 York Rd., Towson, Maryland 21252, USA
| | - Jeffrey W Lynn
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - Nicholas P Butch
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - Heather Chen-Mayer
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | | | - M S Osofsky
- Naval Research Laboratory, Washington, DC 20375, USA
| | - Igor I Smolyaninov
- Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742, USA
- Saltenna LLC, 1751 Pinnacle Drive #600 McLean, Virginia 22102, USA
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5
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Weber F, Rosenkranz S, Pintschovius L, Castellan JP, Osborn R, Reichardt W, Heid R, Bohnen KP, Goremychkin EA, Kreyssig A, Hradil K, Abernathy DL. Electron-phonon coupling in the conventional superconductor YNi2B2C at high phonon energies studied by time-of-flight neutron spectroscopy. PHYSICAL REVIEW LETTERS 2012; 109:057001. [PMID: 23006199 DOI: 10.1103/physrevlett.109.057001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 03/26/2012] [Indexed: 06/01/2023]
Abstract
We report an inelastic neutron scattering investigation of phonons with energies up to 159 meV in the conventional superconductor YNi(2)B(2)C. Using the sweep mode, a newly developed time-of-flight technique involving the continuous rotation of a single crystal specimen, allowed us to measure a four-dimensional volume in (Q, E) space and, thus, determine the dispersion surface and linewidths of the A(1g) (≈102 meV) and A(u) (≈159 meV) type phonon modes over the whole Brillouin zone. Despite of having linewidths of Γ=10 meV, A(1g) modes do not strongly contribute to the total electron-phonon coupling constant λ. However, experimental linewidths show a remarkable agreement with ab initio calculations over the complete phonon energy range, demonstrating the accuracy of such calculations in a rare comparison to a comprehensive experimental data set.
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Affiliation(s)
- F Weber
- Materials Science Division, Argonne National Laboratory, Illinois 60439, USA.
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7
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Raymond S, Kuwahara K, Kaneko K, Iwasa K, Kohgi M, Hiess A, Flouquet J, Metoki N, Sugawara H, Aoki Y, Sato H. Excitation spectrum of PrOs(4)Sb(12) under a magnetic field. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:215702. [PMID: 21825559 DOI: 10.1088/0953-8984/21/21/215702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The evolution of the magnetic excitation spectrum of the heavy fermion superconductor PrOs(4)Sb(12) was studied by inelastic neutron scattering on crossing the critical field H(c2) for superconductivity at low temperature. The peak positions in energy and the peak intensities of the modes of the triplet split by magnetic field confirm the known crystal field parameters for PrOs(4)Sb(12) in T(h) symmetry. A selective broadening of the lineshape occurs on increasing the magnetic field: the linewidth of the upper mode of the triplet increases while the one of the middle mode does not.
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Affiliation(s)
- S Raymond
- CEA-DSM/INAC/SPSMS, F-38054 Grenoble, France
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8
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Weber F, Kreyssig A, Pintschovius L, Heid R, Reichardt W, Reznik D, Stockert O, Hradil K. Direct observation of the superconducting gap in phonon spectra. PHYSICAL REVIEW LETTERS 2008; 101:237002. [PMID: 19113582 DOI: 10.1103/physrevlett.101.237002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Indexed: 05/27/2023]
Abstract
We show that the superconducting energy gap 2Delta can be directly observed in phonon spectra, as predicted by recent theories. In addition, since each phonon probes the gap on only a small part of the Fermi surface, the gap anisotropy can be studied in detail. Our neutron scattering investigation of the anisotropic conventional superconductor YNi2B2C demonstrates this new application of phonon spectroscopy.
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Affiliation(s)
- F Weber
- Forschungszentrum Karlsruhe, Institut für Festkörperphysik, P.O. Box 3640, D-76021 Karlsruhe, Germany.
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9
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Ivanovskii AL. Intermetallic borocarbides: electronic structure, chemical bonding, and properties. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc1998v067n05abeh000404] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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10
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Yokoya T, Kiss T, Watanabe T, Shin S, Nohara M, Takagi H, Oguchi T. Ultrahigh-resolution photoemission spectroscopy of Ni borocarbides: direct observation of the superconducting gap and a change in gap anisotropy by impurity. PHYSICAL REVIEW LETTERS 2000; 85:4952-4955. [PMID: 11102159 DOI: 10.1103/physrevlett.85.4952] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2000] [Indexed: 05/23/2023]
Abstract
We have performed ultrahigh-resolution photoemission spectroscopy of Y(Ni1-xPtx)2B2C ( x = 0.0 and 0.2) in order to study the changes in the density of states across the superconducting transition. Because of a drastic increase in energy resolution, we clearly observe the opening of superconducting gaps across T(c) in both compounds. Furthermore, we find a small but significant difference in the superconducting-state spectral shape. This can be explained in terms of reduction in gap anisotropy by introducing impurities and provides spectroscopic evidence for an anisotropic s-wave gap in YNi2B2C.
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Affiliation(s)
- T Yokoya
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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