# Spin-dependent thermoelectric phenomena in a quantum dot attached to ferromagnetic and superconducting electrodes

## TL;DR

This paper explores how spin-dependent thermoelectric effects arise in a quantum dot system connected to ferromagnetic and superconducting electrodes, highlighting the interplay of Andreev and single-particle tunneling.

## Contribution

It provides a theoretical analysis of thermoelectric properties in hybrid quantum dot systems with ferromagnetic and superconducting leads, considering the effects of Coulomb interaction and superconducting gap.

## Key findings

- Large thermopower and figure of merit due to superconducting gap edges
- Spin thermoelectric phenomena observed in ferromagnetic-superconductor systems
- Influence of Coulomb interaction on transport properties

## Abstract

We investigate transport and thermoelectric properties of hybrid systems based on a single-level quantum dot and one superconducting lead. The other lead is generally normal-metallic ferromagnet. In the latter case single-particle transport is spin-polarized. Our main interest is in the interplay of Andreev tunneling of Cooper pairs and single-particle tunneling. The latter is responsible for relatively large thermopower and figure of merit due to a diverging density of single-particle states at the superconducting gap edges. System with ferromagnetic and superconducting leads can also reveal spin thermoelectric phenomena. Finite superconducting gap is considered within the BCS theory, and the thermoelectric coefficients are calculated by means of nonequilibrium Green's function technique within Hartree-Fock like approximation with respect to the intradot Coulomb interaction.