A Thermoelectric Heat Engine with Ultracold Atoms

TLDR

Thermoelectric effects arise from reversible coupling between heat and particle flows and serve as fundamental probes for materials with applications to cooling and power generation. We demonstrate thermoelectricity in a fermionic cold‑atom channel, showing that its magnitude and energy‑conversion efficiency can be tuned by geometry or disorder, matching a Landauer–Büttiker model and establishing a controllable cold‑atom heat engine.

Abstract

Thermoelectric effects, such as the generation of a particle current by a temperature gradient, have their origin in a reversible coupling between heat and particle flows. These effects are fundamental probes for materials and have applications to cooling and power generation. Here we demonstrate thermoelectricity in a fermionic cold atoms channel, ballistic or diffusive, connected to two reservoirs. We show that the magnitude of the effect and the efficiency of energy conversion can be optimized by controlling the geometry or disorder strength. Our observations are in quantitative agreement with a theoretical model based on the Landauer-Bu ttiker formalism. Our device provides a controllable model-system to explore mechanisms of energy conversion and realizes a cold atom based heat engine.