Spin Seebeck effect and thermoelectric phenomena in superconducting hybrids with magnetic textures or spin-orbit coupling

TL;DR

This paper theoretically explores thermoelectric effects, including the spin Seebeck effect, in superconducting hybrids with magnetic textures or spin-orbit coupling, showing large effects in Josephson systems with minimal magnetic fields.

Contribution

It introduces a quasiclassical framework to calculate thermoelectric responses in superconducting hybrids with complex spin textures and fields, expanding understanding of thermoelectric phenomena in these systems.

Findings

Large thermoelectric effects are achievable in Josephson-based systems with small magnetic fields.

The framework allows for arbitrary spin textures and fields in calculations.

Superconducting hybrids with magnetic textures or spin-orbit coupling exhibit enhanced thermoelectric responses.

Abstract

We theoretically consider the spin Seebeck effect, the charge Seebeck coefficient, and the thermoelectric figure of merit in superconducting hybrid structures including either magnetic textures or intrinsic spin-orbit coupling. We demonstrate that large magnitudes for all these quantities are obtainable in Josephson-based systems with either zero or a small externally applied magnetic field. This provides an alternative to the thermoelectric effects generated in high-field ($\sim 1$ T) superconducting hybrid systems, which were recently experimentally demonstrated. The systems studied contain either textured ferromagnets, spin-active interfaces, or spin-orbit coupling. We present a framework for calculating the linear thermoelectric response for both spin and charge of a system upon applying temperature and voltage gradients based on quasiclassical theory which allows for arbitrary spin-dependent textures and fields to be conveniently incorporated.