Probing thermoelectric transport with cold atoms

TL;DR

This paper proposes experimental protocols using ultracold fermionic atoms to directly observe thermoelectric effects, such as the Seebeck and Peltier analogues, through transient particle imbalances in a two-terminal setup.

Contribution

It introduces novel experimental protocols to detect thermoelectric effects in ultracold atoms and analyzes their feasibility with realistic experimental parameters.

Findings

Transient particle imbalance indicates thermoelectric transport.

Thermoelectric coupling arises from both constriction and reservoir dilatation.

Protocols are feasible under current experimental conditions.

Abstract

We propose experimental protocols to reveal thermoelectric and thermal effects in the transport properties of ultracold fermionic atoms, using the two-terminal setup recently realized at ETH. We show in particular that, for two reservoirs having equal particle numbers but different temperatures initially, the observation of a transient particle number imbalance during equilibration is a direct evidence of thermoelectric (off-diagonal) transport coefficients. This is a time-dependent analogue of the Seebeck effect, and a corresponding analogue of the Peltier effect can be proposed. We reveal that in addition to the thermoelectric coupling of the constriction a thermoelectric coupling also arises due to the finite dilatation coefficient of the reservoirs. We present a theoretical analysis of the protocols, and assess their feasibility by estimating the corresponding temperature and particle number imbalances in realistic current experimental conditions.