Josephson response of a conventional and a noncentrosymmetric superconductor coupled via a double quantum dot

TL;DR

This paper investigates how the Josephson current in a junction involving a conventional superconductor and a noncentrosymmetric superconductor with mixed pairing states can reveal the singlet-triplet ratio, especially under magnetic fields.

Contribution

It introduces a method to probe the singlet-triplet ratio in noncentrosymmetric superconductors using Josephson junctions with double quantum dots.

Findings

Current-phase relation depends on singlet-triplet ratio.

Inhomogeneous magnetic fields induce $$-junction behavior.

The approach provides a sensitive probe of pairing symmetry.

Abstract

We consider transport through a Josephson junction consisting of a conventional s-wave superconductor coupled via a double quantum dot to a noncentrosymmetric superconductor with both, singlet and triplet pairing. We calculate the Andreev bound state energies and the associated Josephson current. We demonstrate that the current-phase relation is a sensitive probe of the singlet-triplet ratio in the noncentrosymmetric superconductor. In particular, in the presence of an inhomogeneous magnetic field the system exhibits a $\varphi$-junction behavior.