Transition to Instability in a Kicked Bose-Einstein Condensate

TL;DR

This paper investigates how a Bose-Einstein condensate subjected to periodic kicks transitions from stable quasiperiodic motion to chaos and instability as interaction strength increases, revealing critical thresholds for stability loss.

Contribution

It introduces a nonlinear model of a kicked Bose-Einstein condensate and identifies the critical interaction strength leading to instability and chaos.

Findings

Weak interactions sustain quasiperiodic motion and stability.

Strong interactions cause chaos and exponential growth of noncondensed atoms.

Dynamically localized states are stable under weak interactions but destabilize with strong interactions.

Abstract

A periodically kicked ring of a Bose-Einstein condensate is considered as a nonlinear generalization of the quantum kicked rotor. For weak interactions between atoms, periodic motion (anti-resonance) becomes quasiperiodic (quantum beating) but remains stable. There exists a critical strength of interactions beyond which quasiperiodic motion becomes chaotic, resulting in an instability of the condensate manifested by exponential growth in the number of noncondensed atoms. Similar behavior is observed for dynamically localized states (essentially quasiperiodic motions), where stability remains for weak interactions but is destroyed by strong interactions.