Thermodynamics of energy, charge and spin currents in thermoelectric quantum-dot spin valve

TL;DR

This paper develops a thermodynamically consistent framework for analyzing energy, charge, and spin currents in a thermoelectric quantum-dot spin valve, revealing efficiency regimes and fundamental relations far from equilibrium.

Contribution

It introduces a nonequilibrium Green's function approach combined with full counting statistics to study thermodynamics of spintronic quantum dots, extending linear response theory.

Findings

Identifies regimes of high efficiency far from equilibrium.

Recovers Onsager relations near equilibrium.

Characterizes entropy production and fluctuation theorem symmetry.

Abstract

We provide a thermodynamically consistent description of energy, charge and spin transfers in a thermoelectric quantum-dot spin valve in the collinear configuration based on nonequilibrium Green's function and full counting statistics. We use the fluctuation theorem symmetry and the concept of entropy production to characterize the efficiency with which thermal gradients can transduce charges or spins against their chemical potentials, arbitrary far from equilibrium. Close to equilibrium, we recover the Onsager reciprocal relations and the connection to linear response notions of performance such as the figure of merit. We also identify regimes where work extraction is more efficient far then close from equilibrium.