Probing dynamical criticality near quantum phase transitions

TL;DR

This paper uncovers a universal prethermal regime near quantum phase transitions in 1D spin chains, characterized by self-similarity and governed by the energy gap, revealing new out-of-equilibrium scaling behaviors.

Contribution

It analytically and numerically demonstrates a universal, self-similar prethermal regime near quantum critical points, independent of initial conditions or weak interactions.

Findings

Existence of a universal prethermal regime near quantum phase transitions

Prethermal dynamics exhibit self-similarity and are governed by the energy gap

Out-of-equilibrium scaling function of the order parameter is identified

Abstract

We reveal a prethermal temporal regime upon suddenly quenching to the vicinity of a quantum phase transition in the time evolution of 1D spin chains. The prethermal regime is analytically found to be self-similar, and its duration is governed by the ground-state energy gap. Based on analytical insights and numerical evidence, we show that this critically prethermal regime universally exists independently of the location of the probe site, the presence of weak interactions, or the initial state. Moreover, the resulting prethermal dynamics leads to an out-of-equilibrium scaling function of the order parameter in the vicinity of the transition.