Spontaneous symmetry breaking-induced thermospin effect in superconducting tunnel junctions

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.

Nonlocal thermoelectric engines in hybrid topological Josephson junctions

“…Still, the thermoelectric response of superconductors has a long history since Ginzburg's seminal work [50] and following literature [51,52]. There are various strategies aimed at inducing thermoelectricity in superconducting or proximized systems by explicitly breaking the PH symmetry by means of ferromagnetic correlations [53][54][55][56][57] and nonlocal geometries [53,58,59] or by using nonlinearities [60][61][62][63][64]. Recently, several authors have discussed Andreev interferometers [65][66][67][68][69] and nonlocal thermoelectricity in Cooper pair splitters [70,71], which found experimental confirmations.…”