Dynamic structure factor of a Bose Einstein condensate in a 1D optical lattice

TL;DR

This paper investigates how a one-dimensional optical lattice influences the dynamic structure factor of an interacting Bose-Einstein condensate, revealing oscillatory excitation patterns and enhanced static structure factors due to phononic correlations.

Contribution

It provides new theoretical insights into the effects of optical lattices on BEC excitations, predicting oscillating excitation strengths and amplified static structure factors.

Findings

Excitation strength oscillates with momentum transfer

Excitations vanish at even multiples of the Bragg momentum

Interactions amplify effects on the static structure factor

Abstract

We study the effect of a one dimensional periodic potential on the dynamic structure factor of an interacting Bose Einstein condensate at zero temperature. We show that, due to phononic correlations, the excitation strength towards the first band develops a typical oscillating behaviour as a function of the momentum transfer, and vanishes at even multiples of the Bragg momentum. The effects of interactions on the static structure factor are found to be significantly amplified by the presence of the optical potential. Our predictions can be tested in stimulated photon scattering experiments.