Spectroscopic Temperature Determination of Degenerate Fermi Gases

TL;DR

This paper introduces a simple in-situ spectroscopic method using two-photon Raman probes to accurately measure the temperature of ultra-cold degenerate Fermi gases, applicable to various fermionic states.

Contribution

The paper presents a novel spectroscopic technique for temperature measurement of degenerate Fermi gases using two-photon Raman lineshapes, effective in realistic experimental conditions.

Findings

Able to determine temperatures down to 0.05 T_F

Applicable to different hyperfine states and scattering interactions

Demonstrated with $^6$Li in realistic setups

Abstract

We suggest a simple method for measuring the temperature of ultra-cold gases made of fermions. We show that by using a two-photon Raman probe, it is possible to obtain lineshapes which reveal properties of the degenerate sample, notably its temperature $T$. The proposed method could be used with identical fermions in different hyperfine states interacting via s-wave scattering or identical fermions in the same hyperfine state via p-wave scattering. We illustrate the applicability of the method in realistic conditions for $^6$Li prepared in two different hyperfine states. We find that temperatures down to 0.05 $T_{F}$ can be determined by this {\it in-situ} method.