Enhanced thermoelectric effects in a driven one-dimensional system

TL;DR

This paper demonstrates that external periodic driving can significantly enhance thermoelectric properties, such as the Seebeck coefficient and Onsager coefficient, in a one-dimensional quantum system, especially at low temperatures.

Contribution

It introduces a Floquet scattering theory approach to analyze and show how external driving improves thermoelectric performance in nanoscale systems.

Findings

Seebeck coefficient increases up to 200% at high frequencies due to driving.

Driving enhances the Onsager coefficient, especially with a step barrier present.

Photon-assisted effects are significant at low temperatures when the chemical potential is within the gap.

Abstract

We investigate the thermoelectric properties of a one-dimensional quantum system in the presence of an external driving. We employ Floquet scattering theory to calculate linear-response stationary thermoelectric figures of merit in a single-channel conductor subjected to a periodically varying delta-like potential barrier. We also include a step barrier in one of the leads as a model of a nanoscale inhomogeneous semiconducting system. In the absence of a step barrier, we found that external driving can significantly enhance the Seebeck coefficient, particularly at low temperatures, with a relative increase of up to 200% at high frequencies compared to the static case. In the presence of a step barrier, we found that the thermoelectric Onsager coefficient for the driven case is also enhanced compared to the static case, with a significant photon-assisted effect at low temperatures when the chemical potential is within the semiconductor's gap. Our results demonstrate that external driving can be used to tune and enhance the thermoelectric capabilities of low-electron-density nanodevices.