Time reversal symmetry breaking and zero magnetic field Josephson diode effect in Dirac semimetal Cd3As2-mediated asymmetric SQUIDs

TL;DR

This paper reports the observation of a zero-magnetic-field Josephson diode effect in an asymmetric SQUID mediated by Dirac semimetal Cd3As2, highlighting the role of phase coupling in breaking time reversal symmetry.

Contribution

It demonstrates the zero-field Josephson diode effect in Cd3As2-mediated SQUIDs and links it to phase coupling between surface and bulk superconducting channels.

Findings

Zero-field Josephson diode effect observed in Cd3As2 SQUIDs

Phase coupling breaks time reversal symmetry

Implications for superconducting electronic circuits

Abstract

A zero-magnetic-field Josephson diode effect (JDE) is observed in an asymmetric superconducting quantum interference device (SQUID) mediated by Dirac semimetal Cd3As2. We argue that a phase coupling between the surface and bulk superconducting channels, a unique phenomenon recently identified in the observations of fractional Josephson effect and Leggett modes in Cd3As2, can break time reversal symmetry and therefore give rise to the zero-field JDE. Our results are anticipated to have important implications in superconducting electronic circuit applications.