Thermoelectricity in a junction between interacting cold atomic Fermi gases

TL;DR

This paper theoretically investigates thermoelectric effects in a junction between two interacting ultracold Fermi gases, revealing sharp quasiparticle current features and potential cooling mechanisms via the Peltier effect.

Contribution

It introduces a theoretical framework for analyzing thermoelectric phenomena in strongly interacting ultracold Fermi gases using generalized BCS theory.

Findings

Sharp peaks in quasiparticle currents observed.

Transitions between normal and superconducting states identified.

Peltier effect could enable cooling of ultracold fermionic atoms.

Abstract

A gas of interacting ultracold fermions can be tuned into a strongly interacting regime using a Feshbach resonance. Here we theoretically study quasiparticle transport in a system of two reservoirs of interacting ultracold fermions on the BCS side of the BCS-BEC crossover coupled weakly via a tunnel junction. Using the generalized BCS theory we calculate the time evolution of the system that is assumed to be initially prepared in a non-equilibrium state characterized by a particle number imbalance or a temperature imbalance. A number of characteristic features like sharp peaks in quasiparticle currents, or transitions between the normal and superconducting states are found. We discuss signatures of the Seebeck and the Peltier effect and the resulting temperature difference of the two reservoirs as a function of the interaction parameter $(k_Fa)^{-1}$. The Peltier effect may lead to an additional cooling mechanism for ultracold fermionic atoms.