Giant thermopower in superconducting heterostructures with spin-active interfaces

TL;DR

This paper predicts a significant enhancement of thermoelectric effects in superconducting bilayers with spin-active interfaces, driven by electron-hole imbalance caused by spin-sensitive scattering.

Contribution

It introduces a new mechanism for strong thermoelectric effects in superconducting heterostructures involving spin-active interfaces.

Findings

Thermoelectric currents can reach values comparable to superconducting critical currents.

Electron-hole imbalance is key to the enhanced thermoelectric effect.

The effect is parametrically strong due to spin-sensitive quasiparticle scattering.

Abstract

We predict parametrically strong enhancement of the thermoelectric effect in metallic bilayers consisting of two superconductors separated by a spin-active interface. The physical mechanism for such an enhancement is directly related to electron-hole imbalance generated by spin-sensitive quasiparticle scattering at the interface between superconducting layers. We explicitly evaluate the thermoelectric currents flowing in the system and demonstrate that they can reach maximum values comparable to the critical ones for superconductors under consideration.