Pairing gap and in-gap excitations in trapped fermionic superfluids

TL;DR

This paper analyzes the RF excitation spectrum of trapped atomic Fermi gases with Feshbach resonances, revealing the pairing gap and in-gap excitations, supporting the observation of superfluidity in recent experiments.

Contribution

It provides a theoretical calculation of RF spectra showing the pairing gap and in-gap excitations in fermionic superfluids, aligning with experimental findings.

Findings

RF spectra display pairing gap and in-gap excitations

Supports superfluidity observation in recent experiments

Highlights many-body pairing effects in fermionic gases

Abstract

We consider trapped atomic Fermi gases with Feshbach-resonance enhanced interactions in pseudogap and superfluid temperatures. We calculate the spectrum of RF(or laser)-excitations for transitions that transfer atoms out of the superfluid state. The spectrum displays the pairing gap and also the contribution of unpaired atoms, i.e. in-gap excitations. The results support the conclusion that a superfluid, where pairing is a many-body effect, was observed in recent experiments on RF spectroscopy of the pairing gap.