Kibble-Zurek Scaling in Holographic Quantum Quench : Backreaction

TL;DR

This paper demonstrates that Kibble-Zurek scaling in holographic quantum quenches persists even when including gauge and gravity backreaction, showing that scalar dynamics alone can induce adiabaticity breakdown and scaling.

Contribution

It extends previous work by showing that Kibble-Zurek scaling occurs without scalar self-coupling when backreaction is considered, highlighting the robustness of the scaling mechanism.

Findings

Scaling behavior observed in charge density and energy momentum tensor.

Backreaction does not destroy Kibble-Zurek scaling.

Scalar dynamics induce adiabaticity breakdown leading to scaling.

Abstract

We study gauge and gravity backreaction in a holographic model of quantum quench across a superfluid critical transition. The model involves a complex scalar field coupled to a gauge and gravity field in the bulk. In earlier work (arXiv:1211.1776) the scalar field had a strong self-coupling, in which case the backreaction on both the metric and the gauge field can be ignored. In this approximation, it was shown that when a time dependent source for the order parameter drives the system across the critical point at a rate slow compared to the initial gap, the dynamics in the critical region is dominated by a zero mode of the bulk scalar, leading to a Kibble-Zurek type scaling function. We show that this mechanism for emergence of scaling behavior continues to hold without any self-coupling in the presence of backreaction of gauge field and gravity. Even though there are no zero modes for the metric and the gauge field, the scalar dynamics induces adiabaticity breakdown leading to scaling. This yields scaling behavior for the time dependence of the charge density and energy momentum tensor.