Spectroscopic Bogoliubov features near the unitary limit

TL;DR

This paper investigates the single particle excitation spectrum of ultracold fermionic atoms near the unitary limit, demonstrating that a phenomenological selfenergy model can accurately reproduce experimental spectroscopic data.

Contribution

It introduces a phenomenological selfenergy approach to describe Bogoliubov quasiparticles in ultracold fermions near unitarity, linking preformed pairs to spectroscopic features.

Findings

Selfenergy model fits RF spectroscopy data well

Preformed pairs influence excitation spectra near unitarity

Reproduces experimental lineshapes for 40K atoms

Abstract

We analyze the single particle excitation spectrum of the ultracold fermion atom system close to the unitary limit where there has been found experimental evidence for the Bogoliubov quasiparticles below as well as above the transition temperature Tc. We consider the short-range correlations originating from the preformed pairs and try to reproduce the experimental data adapting phenomenological selfenergy previously used for description of the anti-nodal spectra of the underdoped cuprate superconductors. We show that it fairly fits the lineshapes obtained by the momentum resolved RF spectroscopy for {40}^K atoms.