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arXiv · 2311.14860

Anomalous Josephson diode effect in superconducting multilayers

A. S. Osin·Alex Levchenko·Maxim Khodas
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Abstract

In this study, we explore the Josephson current-phase relation within a planar diffuse tunneling superconducting multilayer junction subjected to a parallel magnetic field. Our investigation involves computing the supercurrent associated with a fixed jump in the phase of the order parameter at each of the two insulating interfaces, allowing us to derive the current-phase relation for the junction. Employing perturbation theory in junction conductance, we determine both the first and second harmonics of the current-phase relation under specific magnetic field conditions. Notably, the presence of a strong spin-orbit interaction in the middle region of the junction introduces an anomalous Josephson effect. The interplay between spin-orbit and Zeeman interactions results in the emergence of an effective vector potential. This specific characteristic induces a phase shift in each harmonic of the current-phase relation without altering the overall shape of the relation. The mechanism for the Josephson diode effect is discussed for disordered junctions of multiband superconductors.

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A. S. Osin, Alex Levchenko, Maxim Khodas. 2024-06-17. Anomalous Josephson diode effect in superconducting multilayers. https://doi.org/10.1103/physrevb.109.184512

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