Bragg spectroscopy of a strongly interacting Bose-Einstein condensate

TL;DR

This paper investigates the excitation spectrum of a strongly interacting Bose-Einstein condensate using Bragg spectroscopy and time-dependent Hartree-Fock-Bogoliubov theory, revealing the impact of momentum-dependent scattering and a new pairing channel.

Contribution

It introduces a theoretical analysis incorporating momentum-dependent scattering effects and identifies a novel pairing channel affecting the spectrum.

Findings

Momentum-dependent scattering dominates the spectrum at large momentum.

Condensation of scattered atoms creates a new pairing channel.

Spectral features are significantly altered by these effects.

Abstract

We study Bragg spectroscopy of a strongly interacting Bose-Einstein condensate using time-dependent Hartree-Fock-Bogoliubov theory. We include approximatively the effect of the momentum dependent scattering amplitude which is shown to be the dominant factor in determining the spectrum for large momentum Bragg scattering. The condensation of the Bragg scattered atoms is shown to significantly alter the observed excitation spectrum by creating a novel pairing channel of mobile pairs.