Dynamics in many-body localized quantum systems without disorder

TL;DR

This paper investigates nonergodic relaxation dynamics in translation-invariant many-body quantum systems, revealing slow, glass-like behavior and a potential phase transition without disorder, with implications for experimental observation.

Contribution

It demonstrates the existence of a disorder-free many-body localized phase with slow dynamics and characterizes its properties and phase boundary.

Findings

Dynamics are nonperturbatively slow in hopping strength.

Density relaxation exhibits a long out-of-equilibrium plateau.

The long plateau duration diverges exponentially with system size.

Abstract

We study the relaxation dynamics of strongly interacting quantum systems that display a kind of many-body localization in spite of their translation-invariant Hamiltonian. We show that dynamics starting from a random initial configuration is nonperturbatively slow in the hopping strength, and potentially genuinely nonergodic in the thermodynamic limit. In finite systems with periodic boundary conditions, density relaxation takes place in two stages, which are separated by a long out-of-equilibrium plateau whose duration diverges exponentially with the system size. We estimate the phase boundary of this quantum glass phase, and discuss the role of local resonant configurations. We suggest experimental realizations and methods to observe the discussed nonergodic dynamics.