Dynamic trapping near a quantum critical point

TL;DR

This paper introduces the concept of dynamic critical trapping in closed quantum systems near a second order quantum critical point, showing how the system can self-trap due to energy absorption from a dynamically driven field.

Contribution

It develops a new theoretical framework for dynamic trapping phenomena in quantum critical systems with a moving driving field, extending the Kibble-Zurek mechanism.

Findings

Identification of dynamic critical trapping as a robust phenomenon

Development of a generalized Kibble-Zurek scaling theory including dynamic fields

Potential implications for early universe physics and cosmology

Abstract

The study of dynamics in closed quantum systems has recently been revitalized by the emergence of experimental systems that are well-isolated from their environment. In this paper, we consider the closed-system dynamics of an archetypal model: spins near a second order quantum critical point, which are traditionally described by the Kibble-Zurek mechanism. Imbuing the driving field with Newtonian dynamics, we find that the full closed system exhibits a robust new phenomenon -- dynamic critical trapping -- in which the system is self-trapped near the critical point due to efficient absorption of field kinetic energy by heating the quantum spins. We quantify limits in which this phenomenon can be observed and generalize these results by developing a Kibble-Zurek scaling theory that incorporates the dynamic field. Our findings can potentially be interesting in the context of early universe physics, where the role of the driving field is played by the inflaton or a modulus.