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arXiv · 1907.03939

Time-Reversal Invariant Superconductivity of Sr$_{2}$RuO$_{4}$ Revealed by Josephson Effects

Satoshi Kashiwaya·Kohta Saitoh·Hiromi Kashiwaya·Masao Koyanagi·Masatoshi Sato·Keiji Yada·Yukio Tanaka·Yoshiteru Maeno
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Abstract

Sr$_{2}$RuO$_{4}$ is one of the most promising candidates of a topological superconductor with broken time-reversal symmetry, because a number of experiments have revealed evidences for a spin-triplet chiral $p$-wave superconductivity. In order to clarify the time-reversal symmetry of Sr$_{2}$RuO$_{4}$, we introduce a novel test that examines the invariance of the Josephson critical current under the inversion of both the current and magnetic fields, in contrast to the detection of a spontaneous magnetic field employed in past experiments. Analyses of the transport properties of the planar and corner Josephson junctions formed between Sr$_{2}$RuO$_{4}$ and Nb reveal the time-reversal invariant superconductivity, most probably helical $p$-wave, of Sr$_{2}$RuO$_{4}$. This state corresponds to a yet-to-be confirmed $topological crystalline superconductivity$ that can host two Majorana edge modes at the surface protected by crystalline mirror symmetry.

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Satoshi Kashiwaya, Kohta Saitoh, Hiromi Kashiwaya, Masao Koyanagi, Masatoshi Sato, Keiji Yada, Yukio Tanaka, Yoshiteru Maeno. 2019-09-26. Time-Reversal Invariant Superconductivity of Sr$_{2}$RuO$_{4}$ Revealed by Josephson Effects. https://doi.org/10.1103/physrevb.100.094530

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