Thermoelectric effect in a superconductor with Bogoliubov Fermi surfaces

TL;DR

This paper theoretically investigates the thermoelectric effect in a superconductor with Bogoliubov-Fermi surfaces, revealing anisotropic thermoelectric coefficients influenced by magnetic field direction, which could confirm the presence of these surfaces.

Contribution

It introduces a theoretical framework for understanding thermoelectric effects in superconductors with Bogoliubov-Fermi surfaces, highlighting anisotropy related to magnetic field orientation.

Findings

Thermoelectric coefficients exhibit significant anisotropy in real space.

Anisotropy is explained by the shape of the Bogoliubov-Fermi surface in momentum space.

Magnetic field direction controls the anisotropic thermoelectric response.

Abstract

We study theoretically the thermoelectric effect in a superconducting state having the Bogoliubov-Fermi surfaces which stays in a thin superconducting layer between a conventional superconductor and an insulator. The thermoelectric coefficients calculated based on the linear response theory show the remarkable anisotropy in real space, which are explained well by the anisotropic shape of the Bogoliubov-Fermi surface in momentum space. Our results indicate a way to check the existence of the Bogoliubov-Fermi surfaces in a stable superconducting state because the anisotropy is controlled by the direction of an applied magnetic field.