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Khasanov R, Ramires A, Grinenko V, Shipulin I, Kikugawa N, Sokolov DA, Krieger JA, Hicken TJ, Maeno Y, Luetkens H, Guguchia Z. In-Plane Magnetic Penetration Depth in Sr_{2}RuO_{4}: Muon-Spin Rotation and Relaxation Study. PHYSICAL REVIEW LETTERS 2023; 131:236001. [PMID: 38134793 DOI: 10.1103/physrevlett.131.236001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 12/24/2023]
Abstract
We report on measurements of the in-plane magnetic penetration depth (λ_{ab}) in single crystals of Sr_{2}RuO_{4} down to ≃0.015 K by means of muon-spin rotation-relaxation. The linear temperature dependence of λ_{ab}^{-2} for T≲0.7 K suggests the presence of nodes in the superconducting gap. This statement is further substantiated by observation of the Volovik effect, i.e., the reduction of λ_{ab}^{-2} as a function of the applied magnetic field. The experimental zero-field and zero-temperature value of λ_{ab}=124(3) nm agrees with λ_{ab}≃130 nm, calculated based on results of electronic structure measurements reported in A. Tamai et al. [High-resolution photoemission on Sr_{2}RuO_{4} reveals correlation-enhanced effective spin-orbit coupling and dominantly local self-energies, Phys. Rev. X 9, 021048 (2019)PRXHAE2160-330810.1103/PhysRevX.9.021048]. Our analysis reveals that a simple nodal superconducting energy gap, described by the lowest possible harmonic of a gap function, does not capture the dependence of λ_{ab}^{-2} on T, so the higher angular harmonics of the energy gap function need to be introduced.
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Affiliation(s)
- Rustem Khasanov
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Aline Ramires
- Laboratory for Theoretical and Computational Physics, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Vadim Grinenko
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 201210, China
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ilya Shipulin
- Leibniz Institute for Solid State and Materials Research, 01069 Dresden, Germany
| | - Naoki Kikugawa
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan
| | - Dmitry A Sokolov
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, 01187 Dresden, Germany
| | - Jonas A Krieger
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Thomas J Hicken
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Yoshiteru Maeno
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
- Toyota Riken - Kyoto University Research Center (TRiKUC), Kyoto 606-8501, Japan
| | - Hubertus Luetkens
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Zurab Guguchia
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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Zhu Z, Papaj M, Nie XA, Xu HK, Gu YS, Yang X, Guan D, Wang S, Li Y, Liu C, Luo J, Xu ZA, Zheng H, Fu L, Jia JF. Discovery of segmented Fermi surface induced by Cooper pair momentum. Science 2021; 374:1381-1385. [PMID: 34709939 DOI: 10.1126/science.abf1077] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Zhen Zhu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Michał Papaj
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xiao-Ang Nie
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hao-Ke Xu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yi-Sheng Gu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xu Yang
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dandan Guan
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shiyong Wang
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yaoyi Li
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Canhua Liu
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jianlin Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhu-An Xu
- Department of Physics, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Hao Zheng
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Liang Fu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jin-Feng Jia
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
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Chen J, Gamża MB, Banda J, Murphy K, Tarrant J, Brando M, Grosche FM. Unconventional Bulk Superconductivity in YFe_{2}Ge_{2} Single Crystals. PHYSICAL REVIEW LETTERS 2020; 125:237002. [PMID: 33337220 DOI: 10.1103/physrevlett.125.237002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/17/2020] [Accepted: 10/09/2020] [Indexed: 06/12/2023]
Abstract
Sharp superconducting transition anomalies observed in a new generation of single crystals establish that bulk superconductivity is intrinsic to high purity YFe_{2}Ge_{2}. Low temperature heat capacity measurements suggest a disorder and field dependent residual Sommerfeld coefficient, consistent with disorder-induced in-gap states as expected for a sign-changing order parameter. The sevenfold reduction in disorder scattering in these new crystals to residual resistivities ≃0.45 μΩ cm was achieved using a new liquid transport growth technique, paving the way for multiprobe experiments investigating the normal and superconducting states of YFe_{2}Ge_{2}.
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Affiliation(s)
- Jiasheng Chen
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | - Monika B Gamża
- Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy, University of Central Lancashire, PR1 2HE Preston, United Kingdom
| | - Jacintha Banda
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Keiron Murphy
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | - James Tarrant
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | - Manuel Brando
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - F Malte Grosche
- Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
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Chu J, Wang T, Ma Y, Feng J, Wang L, Xu X, Li W, Mu G, Xie X. Multiple gaps revealed by low temperature specific heat in the 1111-type CaFe 0.88Co 0.12AsF single crystals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:455602. [PMID: 31341099 DOI: 10.1088/1361-648x/ab34b8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Low-temperature specific heat (SH) is measured on the 1111-type CaFe0.88 Co0.12AsF single crystals under different magnetic fields. A clear SH jump with the height [Formula: see text] mJ mol-1 K-2 is observed at the superconducting transition temperature T c . The electronic SH coefficient [Formula: see text] increases linearly with the field below 5 T and a kink is observed around 5 T, indicating a multi-gap feature in the present system. Such a sign is also reflected in the T c - B data. A detailed analysis shows that this behavior can be interpreted in terms of a two-gap scenario with the ratio [Formula: see text]-4.5.
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Affiliation(s)
- Jianan Chu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China. CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, People's Republic of China. University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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Bang Y, Stewart GR. Superconducting properties of the s±-wave state: Fe-based superconductors. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:123003. [PMID: 28192286 DOI: 10.1088/1361-648x/aa564b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/20/2016] [Indexed: 06/06/2023]
Abstract
Although the pairing mechanism of Fe-based superconductors (FeSCs) has not yet been settled with consensus with regard to the pairing symmetry and the superconducting (SC) gap function, the vast majority of experiments support the existence of spin-singlet sign-changings-wave SC gaps on multi-bands (s±-wave state). This multi-bands±-wave state is a very unique gap stateper seand displays numerous unexpected novel SC properties, such as a strong reduction of the coherence peak, non-trivial impurity effects, nodal-gap-like nuclear magnetic resonance signals, various Volovik effects in the specific heat (SH) and thermal conductivity, and anomalous scaling behaviors with a SH jump and condensation energy versusTc, etc. In particular, many of these non-trivial SC properties can easily be mistaken as evidence for a nodal-gap state such as ad-wave gap. In this review, we provide detailed explanations of the theoretical principles for the various non-trivial SC properties of thes±-wave pairing state, and then critically compare the theoretical predictions with experiments on FeSCs. This will provide a pedagogical overview of to what extent we can coherently understand the wide range of different experiments on FeSCs within thes±-wave gap model.
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Affiliation(s)
- Yunkyu Bang
- Department of Physics, Chonnam National University, Kwangju 500-757, Republic of Korea
| | - G R Stewart
- Physics Department, University of Florida, Gainesville, FL 32611-8440, United States of America
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Wang H, Mao Q, Chen H, Su Q, Dong C, Khan R, Yang J, Chen B, Fang M. Superconductivity and disorder effect in TlNi2Se(2-x)S(x) compounds. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:395701. [PMID: 26381523 DOI: 10.1088/0953-8984/27/39/395701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
After our first discovery of multi-band superconductivity (SC) in the TlNi2Se2 crystal, we successfully grew a series of TlNi2Se(2-x)S(x) (0.0 ≤ x ≤ 2.0) single crystals. Measurements of resistivity, specific heat, and susceptibility were carried out on these crystals. Superconductivity with T(C) = 2.3 K was first observed in the TlNi2S2 crystal, which also appears to involve heavy electrons with an effective mass m* = 13-25 m(b), as inferred from the normal state electronic specific heat and the upper critical field, H(C2)(T). It was found that bulk SC and heavy-electron behavior is preserved in all the studied TlNi2Se(2-x)S(x) samples. In the mixed state, a novel change of the field dependence of the residual specific heat coefficient, γ(N)(H), occurs in TlNi2Se(2-x)S(x) with increasing S content. We also found that the T(C) value changes with the disorder degree induced by the partial substitution of S for Se, characterized by the residual resistivity ratio (RRR). Thus, the TlNi2Se(2-x)S(x) system provides a platform to study the effect of disorder on the multi-band SC.
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Affiliation(s)
- Hangdong Wang
- Hangzhou Key Laboratory of Quantum Matter, Department of Physics, Hangzhou Normal University, Hangzhou 310036, People's Republic of China. Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China
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Kim JS, Stewart GR, Xing LY, Wang XC, Jin CQ. Specific heat versus field for LiFe(1-x)Cu(x)As. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:475701. [PMID: 23103601 DOI: 10.1088/0953-8984/24/47/475701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
LiFeAs is one of the new class of iron superconductors with a bulk [Formula: see text] in the 15-17 K range. We report on the specific heat characterization of single crystal material prepared by self-flux growth techniques with significantly improved properties, including a much decreased residual gamma, γ(r) (≡C/T as T → 0), in the superconducting state. Thus, in contrast to previous explanations of a finite γ(r) in LiFeAs being due to intrinsic states in the superconducting gap, the present work shows that such a finite residual γ in LiFeAs is instead a function of sample quality. Further, since LiFeAs has been characterized as nodeless with multiple superconducting gaps, we report here on its specific heat properties in zero and applied magnetic fields, to compare to similar results on nodal iron superconductors. For comparison, we also investigate LiFe(0.98)Cu(0.02)As, which has the reduced T(c) of ≈9 K and an H(c2) of 15 T. Interestingly, although presumably both LiFeAs and LiFe(0.98)Cu(0.02)As are nodeless, they clearly show a non-linear dependence of the electronic density of states (is proportional to specific heat γ) at the Fermi energy in the mixed state with the applied field, similar to the Volovik effect for nodal superconductors. However, rather than indicating nodal behavior, the satisfactory comparison with a recent theory for γ(H) for a superconductor with two isotropic gaps in the presence of impurities argues for nodeless behavior. Thus, in terms of specific heat in a magnetic field, LiFeAs can serve as the prototypical multiband, nodeless iron superconductor.
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Affiliation(s)
- J S Kim
- Department of Physics, University of Florida, Gainesville, FL 32611-8440, USA
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