Control of magnetism in singlet-triplet superconducting heterostructures

TL;DR

This paper investigates how the magnetization at the interface of singlet and triplet superconductors depends on the triplet order parameter structure and phase difference, revealing controllable magnetic properties for superconducting heterostructures.

Contribution

It provides a detailed analysis of interface magnetization behavior for various triplet pairing symmetries and links it to Andreev bound states and symmetry considerations.

Findings

Magnetization vanishes at zero phase difference for equal spin helical pairing.

Magnetization follows a cos(φ) pattern for opposite spin chiral pairing.

Higher harmonic behaviors are observed for mixed symmetry pairing.

Abstract

We analyze the magnetization at the interface between singlet and triplet superconductors and show that its direction and dependence on the phase difference across the junction are strongly tied to the structure of the triplet order parameter as well as to the pairing interactions. We consider equal spin helical, opposite spin chiral, and mixed symmetry pairing on the triplet side and show that the magnetization vanishes at $\phi=0$ only in the first case, follows approximately a $\cos\phi$ behavior for the second, and shows higher harmonics for the last configuration. We trace the origin of the magnetization to the magnetic structure of the Andreev bound states near the interface, and provide a symmetry-based explanation of the results. Our findings can be used to control the magnetization in superconducting heterostructures and to test symmetries of spin-triplet superconductors.