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Li H, Wang H, Gao W, Chen Z, Han Y, Zhu X, Tian M. Thickness Dependence of Superconductivity in Layered Topological Superconductor β-PdBi 2. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2826. [PMID: 34835590 PMCID: PMC8618462 DOI: 10.3390/nano11112826] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/13/2021] [Accepted: 10/20/2021] [Indexed: 11/16/2022]
Abstract
We report a systematic study on the thickness-dependent superconductivity and transport properties in exfoliated layered topological superconductor β-PdBi2. The superconducting transition temperature Tc is found to decrease with the decreasing thickness. Below a critical thickness of 45 nm, the superconductivity is suppressed, but followed by an abrupt resistance jump near Tc, which is in opposite to the behavior in a superconductor. We attribute suppressed Tc to the enhanced disorder as the thickness decreases. The possible physical mechanisms were discussed for the origination of sharply increased resistance in thinner β-PdBi2 samples.
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Affiliation(s)
- Huijie Li
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China; (H.L.); (H.W.)
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, China; (Z.C.); (Y.H.); (X.Z.); (M.T.)
| | - Huanhuan Wang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China; (H.L.); (H.W.)
| | - Wenshuai Gao
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China; (H.L.); (H.W.)
| | - Zheng Chen
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, China; (Z.C.); (Y.H.); (X.Z.); (M.T.)
- Department of Physics, University of Science and Technology of China, Hefei 230031, China
| | - Yuyan Han
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, China; (Z.C.); (Y.H.); (X.Z.); (M.T.)
| | - Xiangde Zhu
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, China; (Z.C.); (Y.H.); (X.Z.); (M.T.)
| | - Mingliang Tian
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei 230031, China; (Z.C.); (Y.H.); (X.Z.); (M.T.)
- School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China
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Khodas M, Levchenko A, Catelani G. Quantum-fluctuation effects in the transport properties of ultrathin films of disordered superconductors above the paramagnetic limit. PHYSICAL REVIEW LETTERS 2012; 108:257004. [PMID: 23004644 DOI: 10.1103/physrevlett.108.257004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Indexed: 06/01/2023]
Abstract
We study the transport in ultrathin disordered film near the quantum critical point induced by the Zeeman field. We calculate corrections to the normal state conductivity due to quantum pairing fluctuations. The fluctuation-induced transport is mediated by virtual rather than real quasiparticle excitations. We find that at zero temperature, where the corrections come from purely quantum fluctuations, the Aslamazov-Larkin paraconductivity term, the Maki-Thompson interference contribution, and the density of states effects are all of the same order. The total correction leads to the negative magnetoresistance. This result is in qualitative agreement with the recent transport observations in the parallel magnetic field of the homogeneously disordered amorphous films and superconducting two-dimensional electron gas realized at the oxide interfaces.
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Affiliation(s)
- M Khodas
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
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Loh YL, Trivedi N, Xiong YM, Adams PW, Catelani G. Origin of excess low-energy states in a disordered superconductor in a Zeeman field. PHYSICAL REVIEW LETTERS 2011; 107:067003. [PMID: 21902361 DOI: 10.1103/physrevlett.107.067003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 06/25/2011] [Indexed: 05/31/2023]
Abstract
Tunneling density of states measurements of disordered superconducting Al films in high Zeeman fields reveal a significant population of subgap states which cannot be explained by standard BCS theory. We provide a natural explanation of these excess states in terms of a novel disordered Larkin-Ovchinnikov phase that occurs near the spin-paramagnetic transition at the Chandrasekhar-Clogston critical field. The disordered Larkin-Ovchinnikov superconductor is characterized by a pairing amplitude that changes sign at domain walls. These domain walls carry magnetization and support Andreev bound states that lead to distinct spectral signatures at low energy.
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Affiliation(s)
- Y L Loh
- Department of Physics, The Ohio State University, Columbus, 43210, USA
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Wu XS, Adams PW, Catelani G. Orbital response of evanescent cooper pairs in paramagnetically limited Al films. PHYSICAL REVIEW LETTERS 2005; 95:167001. [PMID: 16241832 DOI: 10.1103/physrevlett.95.167001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2005] [Revised: 06/14/2005] [Indexed: 05/05/2023]
Abstract
We report a detailed study of the pairing resonance via tunneling density of states in ultrathin superconducting Al films in supercritical magnetic fields. Particular emphasis is placed on the effects of the perpendicular component of the magnetic field on the resonance energy and magnitude. Though the resonance is broadened and attenuated by H(perpendicular) as expected, its energy is shifted upward linearly with H(perpendicular). Extension of the original theory of the resonance to include strong perpendicular fields shows that at sufficiently large H(perpendicular) the overlap of the broadened resonance tail with the underlying degenerate Fermi sea alters the spectral distribution of the resonance via the exclusion principle. This leads to the shift of the resonance feature to higher energy.
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Affiliation(s)
- X S Wu
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, 70803, USA
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Adams PW. Field-induced spin mixing in ultrathin superconducting Al and be films in high parallel magnetic fields. PHYSICAL REVIEW LETTERS 2004; 92:067003. [PMID: 14995264 DOI: 10.1103/physrevlett.92.067003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2003] [Indexed: 05/24/2023]
Abstract
We report spin-dependent electron density of states (DOS) studies of ultrathin superconducting Al and Be films in high parallel magnetic fields. Superconductor-insulator-superconductor (SIS) tunneling spectra are presented in which both the film and the counterelectrode are in the paramagnetic limit. This SIS configuration is exquisitely sensitive to spin mixing and/or spin flip processes which are manifest as DOS singularities at eV=2 Delta(0)+/-eV(z). Both our Al and Be data show a well defined subgap peak whose magnitude grows dramatically as the parallel critical field is approached. Though this feature has previously been attributed to spin-orbit scattering, it is more consistent with fluctuations into a field induced mixed-spin state.
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Affiliation(s)
- P W Adams
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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Kim K, Lee HJ. Magnetic-field-driven superconductor-insulator transition in granular In/InOx films. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:13152-13157. [PMID: 9985176 DOI: 10.1103/physrevb.54.13152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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7
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Karpinska K, Malinowski A, Cieplak MZ, Guha S, Gershman S, Kotliar G, Skoskiewicz T, Plesiewicz W, Berkowski M, Lindenfeld P. Magnetic-Field Induced Superconductor-Insulator Transition in the La2-xSrxCuO4 System. PHYSICAL REVIEW LETTERS 1996; 77:3033-3036. [PMID: 10062114 DOI: 10.1103/physrevlett.77.3033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Wu W, Williams J, Adams PW. Zeeman Splitting of the Coulomb Anomaly: A Tunneling Study in Two Dimensions. PHYSICAL REVIEW LETTERS 1996; 77:1139-1142. [PMID: 10063000 DOI: 10.1103/physrevlett.77.1139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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9
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Kagawa K, Inagaki K, Tanda S. Superconductor-insulator transition in ultrathin Pb films: Localization and superconducting coherence. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:R2979-R2982. [PMID: 9983900 DOI: 10.1103/physrevb.53.r2979] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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10
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Bar-Sadeh E, Millo O. Observation of an interplay between single-electron charging effects and superconductivity in YNi2B2C. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:3482-3486. [PMID: 9983861 DOI: 10.1103/physrevb.53.3482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Black CT, Ralph DC, Tinkham M. Spectroscopy of the superconducting gap in individual nanometer-scale aluminum particles. PHYSICAL REVIEW LETTERS 1996; 76:688-691. [PMID: 10061522 DOI: 10.1103/physrevlett.76.688] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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12
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Hsu SY, Chervenak JA, Valles JM. Magnetic field enhanced order parameter amplitude fluctuations in ultrathin films near the superconductor-insulator transition. PHYSICAL REVIEW LETTERS 1995; 75:132-135. [PMID: 10059133 DOI: 10.1103/physrevlett.75.132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Wu W, Adams P. Avalanches and Slow Relaxation: Dynamics of Ultrathin Granular Superconducting Films in a Parallel Magnetic Field. PHYSICAL REVIEW LETTERS 1995; 74:610-613. [PMID: 10058801 DOI: 10.1103/physrevlett.74.610] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Wu W, Goodrich RG, Adams PW. Spin-paramagnetic transition of ultrathin granular Al films in a tilted magnetic field. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:1378-1380. [PMID: 9978310 DOI: 10.1103/physrevb.51.1378] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Wu W, Adams PW. Electric-field tuning of the superconductor-insulator transition in granular Al films. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:13065-13068. [PMID: 9975493 DOI: 10.1103/physrevb.50.13065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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