Enhanced thermopower under time-dependent gate voltage

TL;DR

This paper derives formal expressions for time-dependent energy and heat currents in nanoscale devices, showing that transient thermoelectric properties like the Seebeck coefficient can be significantly enhanced using voltage pulses.

Contribution

It introduces a theoretical framework for analyzing time-dependent thermoelectric effects and demonstrates the potential for transient enhancement of thermopower in nanostructures.

Findings

Seebeck coefficient can be enhanced up to 40% transiently

Analytical linear responses for thermoelectric coefficients derived

Time-dependent energy and heat currents formalism developed

Abstract

We derive formal expressions of time-dependent energy and heat currents through a nanoscopic device using the Keldysh nonequilibrium Green function technique. Numerical results are reported for a metal/dot/metal junction where the dot level energy is abruptly changed by a step-shaped voltage pulse. Analytical linear responses are obtained for the time-dependent thermoelectric coefficients. We show that the Seebeck coefficient can be enhanced in the transient regime up to an amount (here rising 40%) controlled by both the dot energy and the height of the voltage step.