Critical property of the geometric phase in the Dicke model

Gang Chen, Juqi Li, J.-Q. Liang
2006 Physical Review A. Atomic, Molecular, and Optical Physics  
We obtain the ground-state energy level and associated geometric phase in the Dicke model analytically by means of the Holstein-Primakoff transformation and the boson expansion approach in the thermodynamic limit. The non-adiabatic geometric phase induced by the photon field is derived with the time-dependent unitary transformation. It is shown that the quantum phase transition characterized by the non-analyticity of the geometric phase is remarkably of the first-order. We also investigate the
more » ... caling behavior of the geometric phase at the critical point, which can be measured in a practical experiment to detect the quantum phase transition.
doi:10.1103/physreva.74.054101 fatcat:dqevatrkojd5lnpyjl666fyksm