arXiv:1002.2039 · Physical Review A

Overlap of quantum many-body states with a separable state and phase transitions in the Dicke model: Zero and finite temperature

H. T. Cui

Published Apr 30, 2010• 4 citations

Abstract

Overlap with the separable state is introduced in this article for the purpose of characterizing the overall correlation in many-body systems. This definition has clear geometric and physical meaning and moreover can be considered as the generalization of the concept of the Anderson orthogonality catastrophe. As an exemplification, it is used to mark the phase transition in the Dicke model for zero and finite temperatures, and the discussion shows that it can faithfully reflect the phase transition properties of this model whether for zero or finite temperature. Furthermore, the overlap for the ground state also indicates the appearance of multipartite entanglement in the Dicke model.

DOI: 10.1103/physreva.81.042112

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