Excited-State Quantum Phase Transitions in Dicke Superradiance Models
Statistical Mechanics
2013-10-22 v1 Quantum Gases
Quantum Physics
Abstract
We derive analytical results for various quantities related to the excited-state quantum phase transitions in a class of Dicke superradiance models in the semiclassical limit. Based on a calculation of a partition sum restricted to Dicke states, we discuss the singular behavior of the derivative of the density of states and find observables like the mean (atomic) inversion and the boson (photon) number and its fluctuations at arbitrary energies. Criticality depends on energy and a parameter that quantifies the relative weight of rotating versus counter-rotating terms, and we find a close analogy to the logarithmic and jump-type non-analyticities known from the Lipkin-Meshkov-Glick model.
Cite
@article{arxiv.1306.6435,
title = {Excited-State Quantum Phase Transitions in Dicke Superradiance Models},
author = {Tobias Brandes},
journal= {arXiv preprint arXiv:1306.6435},
year = {2013}
}
Comments
14 pages, 3 figures