Thermoelectric study of the time-dependent Resonant Level Model

TL;DR

This paper analytically and numerically investigates the thermoelectric properties of a time-dependent resonant level model, focusing on particle and heat currents, and explores how driving the quantum dot affects efficiency.

Contribution

It provides analytical formulas for time-dependent currents in a driven quantum dot model and compares them with numerical results beyond the wide-band limit.

Findings

Transient efficiency increase is observed but cancels out at long times.

Analytical formulas are derived for time-dependent particle and heat currents.

Numerical simulations validate the analytical results and explore different pulse shapes.

Abstract

We study the non-interacting time-dependent resonant level model mimicking a driven quantum dot connected through leads to two electronic reservoirs held at different temperatures and electrochemical potentials. Using a scattering approach, we provide analytical formulas of the time-dependent particle currents, heat currents, and input driving power under the wide-band limit approximation. We also derive Landauer formulas for the corresponding time-integrated quantities when the perturbation applied on the dot is of finite duration. Then, we focus on the case of a single square pulse, benchmark our analytical results against numerical ones that are valid beyond the wide-band limit, and perform numerical simulations for a smooth square pulse and a periodic square pulse train. Finally, we discuss whether the efficiency of the device in a stationary Seebeck configuration can be enhanced by driving the dot potential. We find numerically that the transient increase of the efficiency observed in some cases is eventually cancelled out at long times.