Exploring super-radiant phase transitions via coherent control of a   multi-qubit--cavity system
  We propose the use of coherent control of a multi-qubit--cavity QED system in order to explore novel phase transition phenomena in a general class of multi-qubit--cavity systems. In addition to atomic systems, the associated super-radiant phase transitions 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. 
Timothy C. Jarrett, Chiu Fan Lee and Neil F. Johnson