Giant Enhancement of the Thermo-Particle Transport Figure of Merit and Breakdown of the Wiedemann-Franz Law in Unitary Fermi Gases

TL;DR

This paper theoretically explores the unique thermo-particle transport properties of unitary Fermi gases, revealing a significant enhancement in the figure of merit and a breakdown of the Wiedemann-Franz law due to preformed Cooper pairs.

Contribution

It demonstrates the drastic enhancement of the transport figure of merit and the breakdown of Fermi liquid behavior in unitary Fermi gases, highlighting their distinct transport characteristics.

Findings

Transport figure of merit is drastically enhanced in the unitary regime.

Lorentz number violates the Wiedemann-Franz law in these systems.

Transport properties are attributed to preformed Cooper pairs.

Abstract

We theoretically investigate the thermo-particle transport properties of an unitary Fermi gas be- tween two reservoirs connected by a quantum point contact. We find several distinguished properties that are qualitatively different from those of weak or non-interacting gas systems. The particle trans- port figure of merit is drastically enhanced in the unitary regime and it increases as the transmission coefficient increases, exactly opposite to the behavior in the weak or non-interacting gas systems. The Lorentz number violates the Wiedemann-Franz law, demonstrating the breakdown of Fermi liquid. These transport properties are the hallmarks of the unitary Fermi gas and are attributed to the existence of preformed Cooper pairs.