Suppression of Density Fluctuations in a Quantum Degenerate Fermi Gas

TL;DR

This paper demonstrates Pauli suppression of density fluctuations in a quantum degenerate Fermi gas, enabling sensitive thermometry and potential insights into phase transitions in many-body systems.

Contribution

It experimentally observes density fluctuation suppression in an ideal Fermi gas and validates noise measurement as a thermometric tool for quantum gases.

Findings

Strong suppression of density fluctuations for large atom numbers

Noise measurement method provides sensitive low-temperature thermometry

Potential application to study phase transitions in correlated systems

Abstract

We study density profiles of an ideal Fermi gas and observe Pauli suppression of density fluctuations (atom shot noise) for cold clouds deep in the quantum degenerate regime. Strong suppression is observed for probe volumes containing more than 10,000 atoms. Measuring the level of suppression provides sensitive thermometry at low temperatures. After this method of sensitive noise measurements has been validated with an ideal Fermi gas, it can now be applied to characterize phase transitions in strongly correlated many-body systems.