A hybrid superconducting quantum dot acting as an efficient charge and spin Seebeck diode

TL;DR

This paper introduces a highly efficient thermoelectric diode based on a hybrid superconducting quantum dot, demonstrating strong nonlinear current behavior and tunability via external parameters, with potential for advanced thermoelectric applications.

Contribution

The work presents a novel quantum dot-based thermoelectric diode with tunable nonlinear current characteristics, supported by a gauge-invariant transport theory accounting for electron interactions.

Findings

Strong diode-like nonlinear current behavior in forward direction

Current nearly vanishes in backward direction under negative thermal gradients

Device performance can be tuned with gate potentials, Zeeman splittings, or lead magnetizations

Abstract

We propose a highly efficient thermoelectric diode device built from the coupling of a quantum dot with a normal or ferromagnetic electrode and a superconducting reservoir. The current shows a strongly nonlinear behavior in the forward direction (positive thermal gradients) while it almost vanishes in the backward direction (negative thermal gradients). Our discussion is supported by a gauge-invariant current-conserving transport theory accounting for electron-electron interactions inside the dot. We find that the diode behavior is greatly tuned with external gate potentials, Zeeman splittings or lead magnetizations. Our results are thus relevant for the search of novel thermoelectric devices with enhanced functionalities.