Non-equilibrium dynamics of ultracold lattice bosons inside a cavity

TL;DR

This paper investigates the non-equilibrium dynamics of ultracold lattice bosons in a cavity, revealing different scaling regimes during phase transitions influenced by quench rates, with implications for understanding defect formation.

Contribution

It demonstrates the existence of a threshold quench rate that separates Kibble-Zurek scaling from saturation behavior in cavity-mediated bosonic systems.

Findings

Power-law scaling of correlation length below threshold quench rate

Saturation of defect density above threshold quench rate

Distinct dynamic regimes explained by relaxation time and quench rate comparison

Abstract

We study the non-equilibrium quench dynamics crossing a continuous phase transition between the charge density wave (CDW) and supersolid (SS) phases of a bosonic lattice gas with cavity-mediated interactions. When changing the hopping amplitude in the Hamiltonian as a function of time, we investigate the scaling behavior of the correlation length and vortex density with respect to the quench time and find that there is a threshold of the quench rate separating two distinct scaling regimes. When slowly varying the system below that threshold, we find a power-law scaling as predicted by the Kibble-Zurek mechanism (KZM). While considering fast quench above that threshold, a deviation from the KZM prediction occurs, manifested by a saturation of the defect density. We further show that such distinct scaling behaviors during different dynamic procedures can be understood through comparing the relaxation time and the quench rate.