All-optical pump-and-probe detection of dynamical correlations in a two-dimensional Fermi gas

TL;DR

This paper introduces an all-optical pump-and-probe method to measure dynamical correlations in a strongly-interacting two-dimensional Fermi gas, enabling the extraction of Green functions, superfluid gaps, and quasiparticle dispersions.

Contribution

It presents a novel optical technique for probing dynamical correlations and quasiparticle properties in ultracold Fermi gases, validated through numerical and analytical analysis.

Findings

Effective measurement of the one-particle Green function

Protocols for extracting superfluid gap

Method applicable to normal and superfluid states

Abstract

We propose an all-optical scheme to probe the dynamical correlations of a strongly-interacting gas of ultracold atoms. The proposed technique is based on a pump-and-probe scheme: a coherent light pulse is initially converted into an atomic coherence and later retrieved after a variable storage time. The efficiency of the proposed method to measure the one-particle Green function of the gas is validated by numerical and analytical calculations of the expected signal for the two cases of a normal Fermi gas and a BCS superfluid state. Protocols to extract the superfluid gap and the full quasi-particle dispersions are discussed.