Probing quasi-particle states in strongly interacting atomic gases by momentum-resolved Raman photoemission spectroscopy

TL;DR

This paper explores a momentum-resolved Raman spectroscopy method to probe quasi-particle states in strongly interacting ultracold atomic gases, offering insights similar to solid-state ARPES and aligning with recent experimental results.

Contribution

It introduces a novel Raman spectroscopy technique for ultracold atoms, inspired by ARPES, capable of analyzing spectral functions across the BEC-BCS crossover.

Findings

Quantitative spectra for different regimes along the BEC-BCS crossover.

Agreement with recent RF spectroscopy experimental data.

Advantages over existing spectroscopic techniques.

Abstract

We investigate a momentum-resolved Raman spectroscopy technique which is able to probe the one-body spectral function and the quasi-particle states of a gas of strongly interacting ultracold atoms. This technique is inspired by Angle-Resolved Photo-Emission Spectroscopy, a powerful experimental probe of electronic states in solid-state systems. Quantitative examples of experimentally accessible spectra are given for the most significant regimes along the BEC-BCS crossover. When the theory is specialized to RF spectroscopy, agreement is found with recent experimental data. The main advantages of this Raman spectroscopy over existing techniques are pointed out.