Violation of the Wiedemann-Franz Law for ultracold atomic gases

TL;DR

This paper investigates energy and particle transport in strongly interacting 1D bosonic gases, revealing particle-energy current separation, violation of the Wiedemann-Franz law, and emergent thermoelectric effects, with implications for ultracold atom experiments.

Contribution

It demonstrates the violation of the Wiedemann-Franz law and the emergence of thermoelectric effects in ultracold bosonic gases beyond linear spectrum approximation.

Findings

Particle- and energy-current separation observed.

Violation of the Wiedemann-Franz law predicted.

Thermoelectric effects emerge with tunable interactions and temperature.

Abstract

We study energy and particle transport for one-dimensional strongly interacting bosons through a single channel connecting two atomic reservoirs. We show the emergence of particle- and energy- current separation, leading to the violation of the Wiedemann-Franz law. As a consequence, we predict different time scales for the equilibration of temperature and particle imbalances between the reservoirs. Going beyond the linear spectrum approximation, we show the emergence of ther- moelectric effects, which could be controlled by either tuning interactions or the temperature. Our results describe in a unified picture fermions in condensed matter devices and bosons in ultracold atom setups. We conclude discussing the effects of a controllable disorder.