Bose-Einstein condensate of kicked rotators with time-dependent interaction

TL;DR

This paper investigates a modified quantum kicked rotator with a time-dependent interaction parameter, revealing exponential energy growth and strong chaos, which differ from traditional models with constant interaction.

Contribution

It introduces a novel model with time-dependent delta-kicked interaction and derives a recursive relation to describe superdiffusive energy growth.

Findings

Mean kinetic energy grows exponentially over time.

Time-dependent interaction induces strong chaotic behavior.

The model differs significantly from constant-interaction quantum rotators.

Abstract

A modification of the quantum kicked rotator is suggested with a time-dependent delta-kicked interaction parameter which can be realized by a pulsed turn-on of a Feshbach resonance. The mean kinetic energy increases exponentially with time in contrast to a merely diffusive or linear growth for the first few kicks for the quantum kicked rotator with a constant interaction parameter. A recursive relation is derived in a self-consistent random phase approximation which describes this superdiffusive growth of the kinetic energy and is compared with numerical simulations. Unlike in the case of the quantum rotator with constant interaction, a Lax pair is not found. In general the delta-kicked interaction is found to lead to strong chaotic behaviour.