Bragg spectroscopy of an accelerating condensate with solitary-wave behaviour

TL;DR

This paper develops a theoretical framework for analyzing Bragg spectroscopy of an accelerating Bose-Einstein condensate exhibiting solitary-wave behavior, providing approximate solutions and physical insights into the spectral features.

Contribution

It introduces an analytic method based on the Gross-Pitaevskii equation for solitary-wave condensates under acceleration, enabling easier computation of Bragg spectra.

Findings

The method accurately predicts Bragg spectra within specific parameters.

It offers physical understanding of spectral structures in accelerating condensates.

Application demonstrated with a condensate in a time-averaged orbiting potential trap.

Abstract

We present a theoretical treatment of Bragg spectroscopy of an accelerating condensate in a solitary-wave state. Our treatment is based on the Gross-Pitaevskii equation with an optical potential representing the Bragg pulse and an additional external time-dependent potential generating the solitary-wave behaviour. By transforming to a frame translating with the condensate, we derive an approximate set of equations that can be readily solved to generate approximate Bragg spectra. Our analytic method is accurate within a well defined parameter regime and provides physical insight into the structure of the spectra. We illustrate our formalism using the example of Bragg spectroscopy of a condensate in a time-averaged orbiting potential trap.