Remnants of Anderson localization in pre-thermalization induced by white noise

TL;DR

This paper investigates how white noise affects the non-equilibrium dynamics of a disordered quantum Ising chain, revealing pre-thermalization and a transient localization phenomenon similar to Anderson localization.

Contribution

It demonstrates the emergence of pre-thermalization and a noise-induced localization effect in a disordered quantum spin chain under white noise, highlighting the interplay of disorder and noise in quantum dynamics.

Findings

Pre-thermalization occurs in noisy disordered quantum chains.

Intermediate-time localization resembles Anderson localization.

Noise eventually destroys localization, leading to thermalization.

Abstract

We study the non-equilibrium evolution of a one-dimensional quantum Ising chain with spatially disordered, time-dependent, transverse fields characterised by white noise correlation dynamics. We establish pre-thermalization in this model, showing that the quench dynamics of the on-site transverse magnetisation first approaches a metastable state unaffected by noise fluctuations, and then relaxes exponentially fast towards an infinite temperature state as a result of the noise. We also consider energy transport in the model, starting from an inhomogeneous state with two domain walls which separate regions characterised by spins with opposite transverse magnetization. We observe at intermediate time scales a phenomenology akin to Anderson localization: energy remains localised within the two domain walls, until the Markovian noise destroys coherence and accordingly disorder-induced localization, allowing the system to relax towards the late stages of its non-equilibrium dynamics. We benchmark our results with the simpler case of a noisy quantum Ising chain without disorder, and we find that the pre-thermal plateau is a generic property of weakly noisy spin chains, while the phenomenon of pre-thermal Anderson localisation is a specific feature arising from the competition of noise and disorder in the real-time transport properties of the system.