Interactions destroy dynamical localization with strong and weak chaos

TL;DR

This paper investigates how interactions in Bose-Einstein condensates within kicked optical lattices influence dynamical localization, revealing regimes of wave packet spreading characterized by distinct power-law growths.

Contribution

It introduces a qualitative Gross-Pitaevskii model to analyze the impact of interactions on dynamical localization and chaos regimes in quantum kicked rotor systems.

Findings

Energy grows as t^{1/2} in strong chaos regime

Energy growth crosses over to t^{1/3} in weak chaos regime

Results are independent of kicking details

Abstract

Bose-Einstein condensates loaded into kicked optical lattices can be treated as quantum kicked rotor systems. Noninteracting rotors show dynamical localization in momentum space. The experimentally tunable condensate interaction is included in a qualitative Gross-Pitaevskii type model based on two-body interactions. We observe strong and weak chaos regimes of wave packet spreading in momentum space. In the intermediate strong chaos regime the condensate energy grows as $t^{1/2}$. In the asymptotic weak chaos case the growth crosses over into a $t^{1/3}$ law. The results do not depend on the details of the kicking.