Signatures of odd-frequency correlations in the Josephson current of superconductor/ferromagnet hybrid junctions

TL;DR

This paper explores how odd-frequency superconducting correlations influence the Josephson current in superconductor/ferromagnet hybrid junctions, revealing unique temperature-dependent signatures of these correlations.

Contribution

It demonstrates the impact of odd-frequency correlations on Josephson effects between different superconducting symmetries, highlighting their signatures in critical current behavior.

Findings

Temperature dependence of critical current reveals odd-frequency correlations.

Competition between odd/odd and odd/even-frequency couplings affects supercurrent.

Signature of odd-frequency correlations in superconductor/ferromagnet junctions.

Abstract

Contacting a bilayer ferromagnet with a singlet even-frequency superconductor allows for the realization of an effective triplet odd-frequency superconductor. In this work, we investigate the Josephson effect between superconductors with different symmetries (e.g. odd- versus even-frequency). In particular, we study the supercurrent flowing between two triplet odd-frequency superconducting leads through a weak singlet even-frequency superconductor. We show that the peculiar temperature dependence of the critical current below the superconducting transition of the weak superconductor is a signature of the competition between odd/odd-frequency and odd/even-frequency Josephson couplings.