Signatures of two-gap superconductivity in epitaxial La(PtxSi1-x)2 films

ORAL

Abstract

Symmetry plays an important role in superconductivity. In noncentrosymmetric superconductors, the pairing state might become a mixture of spin-singlet and spin-triplet components due to the anti-symmetric spin-orbit coupling (ASOC), which is “protected” by the lack of an inversion center. This mixing can further lead to two-gap physics. We investigated the transport properties of various La(PtxSi1-x)2 thin films grown by molecular beam epitaxy (MBE), where the inversion symmetry and spin-orbit coupling strength are tunable by varying the Pt concentration x. For certain x, magnetoresistance shows a two-step transition at finite temperatures below Tc, and the upper critical field is well described by a two-band model. Furthermore, the current-voltage characteristics, along with the differential resistance measurements, reveal a two-gap structure in magnetic fields up to 1 T. These observations indicate the multi-gap superconductivity in La(PtxSi1-x)2 films.

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Presenters

  • Jian Liao

    Department of Physics, University of Texas at Dallas, Richardson, TX, 75080

Authors

  • Jian Liao

    Department of Physics, University of Texas at Dallas, Richardson, TX, 75080

  • Yunbo Ou

    Dept. Of Physics, Plasma Science and Fusion Center and Francis Bitter Magnet Lab, Massachusetts Institute of Technology, MIT, Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, MIT, Cambridge, MA, 02139

  • Jagadeesh Moodera

    Dept. Of Physics, Plasma Science and Fusion Center and Francis Bitter Magnet Lab, Massachusetts Institute of Technology, MIT, Department of Physics, Massachusetts Institute of Technology, Massachusetts Institute of Technology, Department of Physics, Plasma Science and Fusion Center, and Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, MIT, Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, and Department of Physics, MIT, Francis Bitter Magnet Laboratory and Plasma Science and Fusion Center, MASSACHUSETTS INSTITUTE OF TECHNOLOGY, Plasma Science and Fusion Center and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Physics, Francis Bitter Magnet Laboratory, Plasma Science and Fusion Center, Massachusetts Institute of Technology, Department of Physics, MIT, Cambridge, MA, 02139

  • Xiaoyan Shi

    Department of Physics, University of Texas at Dallas, Department of Physics, University of Texas at Dallas, Richardson, TX, 75080