Quench induced chaotic dynamics of Anderson localized interacting Bose-Einstein condensates in one dimension

TL;DR

This paper investigates how atomic interactions influence localization and induce chaotic dynamics in one-dimensional Bose-Einstein condensates subjected to quasiperiodic and disordered potentials, revealing a link between delocalization and chaos.

Contribution

It demonstrates the emergence of temporal chaos and quasiperiodic routes to chaos in BECs through interaction quenching, connecting spatial delocalization with temporal dynamical complexity.

Findings

Localization weakens with increasing interaction strength.

Chaotic dynamics are confirmed by Lyapunov exponents and power spectral density.

A quasiperiodic route to chaos is identified in the system.

Abstract

We study the effect of atomic interaction on the localization and the associated dynamics of Bose-Einstein condensates in a one-dimensional quasiperiodic optical lattice and random Gaussian disordered potentials. When the interactions are absent, the condensates exhibit localization, which weakens as we increase the interaction strength beyond a threshold value for both potential types. We inspect the localized and delocalized states by perturbing the system via quenching the interaction strength instantaneously to zero and studying the dynamics of the condensate, which we further corroborate using the out-of-time-order correlator. The temporal behaviour of the time correlator displays regular dynamics for the localized state, while it shows temporal chaos for the delocalized state. We confirm this dynamical behaviour by analyzing the power spectral density of the time correlator. We further identify that the condensate admits a quasiperiodic route to chaotic dynamics for both potentials. Finally, we present the variation of the maximal Lyapunov exponents for different nonlinearity and disorder strengths that have a positive value in the regime where the time correlator function shows chaotic behaviour. Through this, we establish the strong connection between the spatially delocalized state of the condensate and its temporal chaos.