Unified superradiant phase transitions

Superradiant phase transitions with three-level systems

First-order superradiant phase transitions in a multiqubit cavity system.

We predict the existence of novel first-order phase transitions in a general class of multiqubit cavity systems. Apart from atomic systems, the associated superradiant phase transition should be observable in a variety of solid-state experimental systems, including the technologically important case of interacting quantum dots coupled to an optical cavity mode.

Superradiant phase transitions and the standard description of circuit QED.

We investigate the equilibrium behavior of a superconducting circuit QED system containing a large number of artificial atoms. It is shown that the currently accepted standard description of circuit QED via an effective model fails in an important aspect: it predicts the possibility of a superradiant phase transition, even though a full microscopic treatment reveals that a no-go theorem for suc...

Comment on "Superradiant phase transitions and the standard description of circuit QED".

Depolarization shift of the superradiant phase transition

Quantum electrodynamics, when applied to a large ensemble of identical atoms, leads to the surprising prediction that a so-called superradiant phase transition takes place above a critical density of the atom gas. In thermal equilibrium and also in the ground state of the system at zero temperature, the atoms in the superradiant phase develop a polarization field with non-vanishing mean value a...