Interaction-driven breakdown of dynamical localization in a kicked quantum gas

Abstract

Quantum interference can terminate energy growth in a continually kicked system, via a single-particle ergodicity-breaking mechanism known as dynamical localization. The effect of many-body interactions on dynamically localized states, while important to a fundamental understanding of quantum decoherence, has remained unexplored despite a quarter-century of experimental studies. We report the experimental realization of a tunably-interacting kicked quantum rotor ensemble using a Bose-Einstein condensate in a pulsed optical lattice. We observe signatures of a prethermal localized plateau, followed for interacting samples by interaction-induced anomalous diffusion with an exponent near one half. Echo-type time reversal experiments establish the role of interactions in destroying reversibility. These results quantitatively elucidate the dynamical transition to many-body quantum chaos, advance our understanding of quantum anomalous diffusion, and delimit some possibilities for protecting quantum information in interacting driven systems.

Protected quantum coherence by gain and loss in a noisy quantum kicked rotor

“…In these experiments, with a periodic sequence of ultrashort laser pulses, the dynamical localization of the molecular angular momentum [94] and the effect of quantum resonance in the rotational excitation [95] were observed. More recently, the effect of many-body interactions on the dynamical localization of Bose-Einstein condensate in a pulsed optical lattice has been experimentally investigated [96].…”