Nonlinear transport in gate-induced 2D Rashba superconductor SrTiO<sub>3</sub>

ORAL

Abstract

A polar conductor with Rashba spin-orbit coupling is a potential material platform for exotic quantum transport and spintronic functionalities [1,2]. One of their inherent properties is the nonreciprocal transport, where the magnetoresistance becomes inequivalent between the rightward and leftward current directions, because of the breaking of both spatial inversion and time reversal symmetries. Such a rectification effect reflecting polar symmetry has been studied at the interface or bulk polar semiconductor [3,4]. However, the mechanism of the nonreciprocity in a polar superconductor remains elusive.
To elucidate the noncentrosymmetric nature of the Rashba superconductor, we have investigated the nonreciprocal transport in gated SrTiO3, which is known as a 2D Rashba superconductor. We found the gigantic enhancement in the nonlinear resistance in the amplitude and phase fluctuation regions. Also, we discuss the possible origins of nonreciprocity in the 2D Rashba superconductor, such as paraconductivity with a parity mixing in the Cooper pairs and rectified vortex-antivortex motions.
[1] E. Lesne et al., Nat. Mater. 15, 1261 (2016).
[2] R. Ohshima et al., Nat. Mater. 16, 609 (2017).
[3] P. He et al., Phys. Rev. Lett. 120, 266802 (2018).
[4] T. Ideue et al., Nat. Phys. 13, 578 (2017).

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Presenters

  • Yuki Itahashi

    • The Univ. of Tokyo, Tokyo, Japan.

Authors

  • Yuki Itahashi

    • The Univ. of Tokyo, Tokyo, Japan.

  • Toshiya Ideue

    • Univ of Tokyo
    • The Univ. of Tokyo, Tokyo, Japan.
    • The University of Tokyo

  • Yu Saito

    • Physics, University of California, Santa Barbara
    • University of California, Santa Barbara
    • University of California at Santa Barbara, Santa Barbara, USA.

  • Sunao Shimizu

    • CRIEPI
    • Central Research Institute of Electric Power Industry, Yokosuka, Japan.

  • Takumi Ouchi

    • Tohoku Univ., Sendai, Japan.
    • IMR, Tohoku Univ.

  • Tsutomu Nojima

    • Tohoku Univ., Sendai, Japan.
    • IMR, Tohoku Univ.

  • Yoshihiro Iwasa

    • Department of Applied Physics, The University of Tokyo
    • Univ of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics (QPEC) Center, The University of Tokyo
    • The Univ. of Tokyo, Tokyo, Japan.
    • The University of Tokyo
    • Applied Physics, the University of Tokyo