Nonequilibrium Quantum Phase Transition in a Hybrid Atom-Optomechanical System
Abstract
We consider a hybrid quantum many-body system formed by both a vibrational mode of a nanomembrane, which interacts optomechanically with light in a cavity, and an ultracold atom gas in the optical lattice of the out-coupled light. After integrating over the light field, an effective Hamiltonian reveals a competition between the localizing potential force and the membrane displacement force. For increasing atom-membrane interaction we find a nonequilibrium quantum phase transition from a localized non-motional phase of the atom cloud to a phase of collective motion. Near the quantum critical point, the energy of the lowest collective excitation vanishes, while the order parameter of the condensate becomes non-zero in the symmetry-broken state. The effect occurs when the atoms and the membrane are non-resonantly coupled.
Cite
@article{arxiv.1710.10257,
title = {Nonequilibrium Quantum Phase Transition in a Hybrid Atom-Optomechanical System},
author = {Niklas Mann and M. Reza Bakhtiari and Axel Pelster and Michael Thorwart},
journal= {arXiv preprint arXiv:1710.10257},
year = {2018}
}