Theory of non-equilibrium thermoelectric effects in nanoscale junctions

TL;DR

This paper develops a quantum open system approach to study non-equilibrium thermoelectric effects in nanoscale junctions, revealing resonant behaviors, local temperature variations, and violations of Fourier's law at the nanoscale.

Contribution

It introduces a dynamic, non-equilibrium framework for thermoelectricity in nanosystems, contrasting with traditional static scattering models.

Findings

Resonant structures and sign sensitivity in thermoelectric response.

Observation of hot spots and temperature oscillations.

Violation of Fourier's law at the nanoscale.

Abstract

Despite its intrinsic non-equilibrium origin, thermoelectricity in nanoscale systems is usually described within a static scattering approach which disregards the dynamical interaction with the thermal baths that maintain energy flow. Using the theory of open quantum systems we show instead that unexpected properties, such as a resonant structure and large sign sensitivity, emerge if the non-equilibrium nature of this problem is considered. Our approach also allows us to define and study a local temperature, which shows hot spots and oscillations along the system according to the coupling of the latter to the electrodes. This demonstrates that Fourier's law -- a paradigm of statistical mechanics -- is violated at the nanoscale.