Spontaneous symmetry breaking-induced thermospin effect in superconducting tunnel junctions

TL;DR

This paper predicts a novel thermo-spin effect in superconducting tunnel junctions caused by spontaneous symmetry breaking, leading to a spin-polarized thermoelectric current driven by temperature bias.

Contribution

It introduces the concept of a spontaneous symmetry breaking-induced thermospin effect in superconducting junctions, a phenomenon not previously described.

Findings

Spin-polarized thermoelectric current generated by temperature bias.

Spontaneous particle-hole symmetry breaking causes the effect.

Spin current exceeds that of polarized cases when thermo-active component dominates.

Abstract

We discuss the charge and the spin tunneling currents between two Bardeen-Cooper-Schrieffer (BCS) superconductors, where one density of states is spin-split. In the presence of a large temperature bias across the junction, we predict the generation of a spin-polarized thermoelectric current. This thermo-spin effect is the result of a spontaneous particle-hole symmetry breaking in the absence of a polarizing tunnel barrier. The two spin components, which move in opposite directions, generate a spin current larger than the purely polarized case when the thermo-active component dominates over the dissipative one.