Heat Capacity of a Strongly-Interacting Fermi Gas

TL;DR

This paper measures the heat capacity of a strongly-interacting Fermi gas, revealing a transition in thermodynamic behavior at a specific temperature range, and providing insights into quantum many-body physics.

Contribution

It presents the first precise measurement of heat capacity in a strongly-interacting Fermi gas using single-parameter thermometry.

Findings

Heat capacity matches that of a normal Fermi gas at higher temperatures.

Deviations from normal Fermi gas behavior are observed at low temperatures.

Identifies a transition point at a specific temperature parameter.

Abstract

We report on the measurement of the heat capacity for an optically-trapped, strongly-interacting Fermi gas of atoms. In the experiments, a precise input of energy to the gas is followed by single-parameter thermometry. The thermometry determines a temperature parameter $\tilde{T}$ from the best fit of a Thomas-Fermi distribution with a fixed Fermi radius to the spatial density of the cloud. At $\tilde{T}=0.33$, we observe a transition between two patterns of behavior: For $\tilde{T}=0.33-2.15$, we find that the heat capacity closely corresponds to that of a trapped normal Fermi gas of atoms with increased mass. At low temperatures $\tilde{T}=0.04-0.33$, the heat capacity clearly deviates from normal Fermi gas behavior.