Coherence and Instability in a Driven Bose-Einstein Condensate: A Fully Dynamical Number-Conserving Approach

TL;DR

This paper presents a fully dynamical, number-conserving approach to analyze a driven Bose-Einstein condensate, revealing damping of noncondensate growth and oscillations in population and coherence, contrasting with first-order predictions.

Contribution

It introduces a second-order, time-dependent method that accurately models condensate depletion and coherence dynamics in periodically driven Bose-Einstein condensates.

Findings

Damping of noncondensate growth in resonant regimes

Oscillations in condensate and noncondensate populations

Enhanced accuracy over first-order descriptions

Abstract

We consider a Bose-Einstein condensate driven by periodic delta-kicks. In contrast to first-order descriptions, which predict rapid, unbounded growth of the noncondensate in resonant parameter regimes, the consistent treatment of condensate depletion in our fully-time-dependent, second-order description acts to damp this growth, leading to oscillations in the (non)condensate population and the coherence of the system.