Optical signatures of quantum phase transitions in a light-matter system

Abstract

Information about quantum phase transitions in conventional condensed matter\nsystems, must be sought by probing the matter system itself. By contrast, we\nshow that mixed matter-light systems offer a distinct advantage in that the\nphoton field carries clear signatures of the associated quantum critical\nphenomena. Having derived an accurate, size-consistent Hamiltonian for the\nphotonic field in the well-known Dicke model, we predict striking behavior of\nthe optical squeezing and photon statistics near the phase transition. The\ncorresponding dynamics resemble those of a degenerate parametric amplifier. Our\nfindings boost the motivation for exploring exotic quantum phase transition\nphenomena in atom-cavity, nanostructure-cavity, and\nnanostructure-photonic-band-gap systems.\n