Short-time universal scaling in an isolated quantum system after a quench

TL;DR

This paper investigates the short-time universal scaling behavior of an isolated quantum scalar field system after a quench, revealing a universal exponent in the pre-thermal regime through renormalization-group analysis.

Contribution

It introduces a novel analysis of short-time universal scaling in quantum systems post-quench using renormalization-group methods near a dynamical critical point.

Findings

Identification of a short-time universal exponent in quantum dynamics

Demonstration of pre-thermal regime behavior

Calculation of the exponent at lowest order in dimensional expansion

Abstract

Renormalization-group methods provide a viable approach for investigating the emergent collective behavior of classical and quantum statistical systems in both equilibrium and nonequilibrium conditions. Within this approach we investigate here the dynamics of an isolated quantum system represented by a scalar $\phi^4$ theory after a global quench of the potential close to a dynamical critical point. We demonstrate that, within a pre-thermal regime, the time dependence of the relevant correlations is characterized by a short-time universal exponent, which we calculate at the lowest order in a dimensional expansion.