Final-state effects in the radio frequency spectrum of strongly interacting fermions

TL;DR

This paper models how final state interactions influence the radio frequency spectrum of a strongly interacting superfluid Fermi gas, revealing both broad peaks and sharp spectral lines related to pair conversions.

Contribution

It introduces a model capturing the effects of final state interactions on RF spectra, including the prediction of a novel bound-bound spectral line.

Findings

Identification of a broad asymmetric peak from Cooper pair break-up

Prediction of a sharp symmetric bound-bound spectral line

Conditions under which the bound-bound line appears

Abstract

We model the impact of final state interactions on the radio frequency spectrum of a strongly interacting two-component superfluid Fermi gas. In addition to a broad asymmetric peak coming from the break-up of Cooper pairs we find that, for appropriate parameters, one can observe a sharp symmetric "bound-bound" spectral line coming from the conversion of Cooper pairs in one channels to pairs/molecules in another.