Interaction-induced impeding of decoherence and anomalous diffusion

TL;DR

This paper investigates how the combination of dissipation and strong interactions influences the dynamics of a bosonic quantum system, revealing complex regimes and a counterintuitive slowdown of decoherence.

Contribution

It demonstrates that strong interactions can impede decoherence caused by dissipation, and maps the long-time dynamics onto a classical non-Brownian diffusion process.

Findings

Three dynamical regimes identified: exponential, power-law, and slow exponential.

Strong interactions slow down decoherence induced by dissipation.

Long-time dynamics resemble a classical non-Brownian diffusion process.

Abstract

We study how the interplay of dissipation and interactions affects the dynamics of a bosonic many-body quantum system. In the presence of both dissipation and strongly repulsive interactions, observables such as the coherence and the compressibility display three dynamical regimes: an initial exponential variation followed by a power-law regime and finally a slow exponential convergence to their asymptotic values corresponding to the infinite temperature state. These very long-time scales arise as dissipation forces the population of states disfavored by interactions. The long-time, strong coupling dynamics are understood by performing a mapping onto a classical diffusion process displaying non-Brownian behavior. While both dissipation and strong interactions tend to suppress coherence when acting separately, we find that strong interaction impedes the decoherence process generated by the dissipation.