Nonequilibrium quench dynamics in quantum quasicrystals

TL;DR

This paper investigates the nonequilibrium behavior of a quasiperiodic quantum Ising chain after a sudden quench, revealing power-law entanglement growth, stretched-exponential magnetization relaxation, and a dynamical phase transition.

Contribution

It provides a detailed analysis of quasiparticle dynamics and identifies a dynamical phase transition in a quasiperiodic quantum system.

Findings

Entanglement entropy grows as a power-law over time.

Magnetization exhibits stretched-exponential relaxation.

A dynamical phase transition is observed in the magnetization dynamics.

Abstract

We study the nonequilibrium dynamics of a quasiperiodic quantum Ising chain after a sudden change in the strength of the transverse field at zero temperature. In particular we consider the dynamics of the entanglement entropy and the relaxation of the magnetization. The entanglement entropy increases with time as a power-law, and the magnetization is found to exhibit stretched-exponential relaxation. These behaviors are explained in terms of anomalously diffusing quasiparticles, which are studied in a wave packet approach. The nonequilibrium magnetization is shown to have a dynamical phase transition.