Nonequilibrium Quantum Phase Transitions in the Dicke Model

TL;DR

This paper investigates nonequilibrium quantum phase transitions in the Dicke model induced by nonadiabatic modulation of atom-field coupling, revealing multistability and both first- and second-order transitions.

Contribution

It demonstrates how nonadiabatic driving enables superradiant phase transitions and uncovers complex multistable behavior in the Dicke model.

Findings

Identification of sidebands enabling superradiant transitions

Observation of multistability at strong driving

Discovery of both first- and second-order phase transitions

Abstract

We establish a set of nonequilibrium quantum phase transitions in the Dicke model by considering a monochromatic nonadiabatic modulation of the atom-field coupling. For weak driving the system exhibits a set of sidebands which allow the circumvention of the no-go theorem which otherwise forbids the occurence of superradiant phase transitions. At strong driving we show that the system exhibits a rich multistable structure and exhibits both first- and second-order nonequilibrium quantum phase transitions.