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arXiv · 0901.2705

Berry Phase and Fidelity in the Dicke model with $A^{2}$ term

Yu-Yu Zhang·Tao Liu·Qing-Hu Chen·Kelin Wang
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Abstract

The instability, so-called the quantum-phase-like transition, in the Dicke model with a rotating-wave approximation for finite $N$ atoms is investigated in terms of the Berry phase and the fidelity. It can be marked by the discontinuous behavior of these quantities as a function of the atom-field coupling parameter. Involving an additional field $A^{2}$ term, it is observed that the instability is not eliminated beyond the characteristic atom-field coupling parameter even for strong interaction of the bosonic fields, contrarily to the previous studies.

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Yu-Yu Zhang, Tao Liu, Qing-Hu Chen, Kelin Wang. 2009-01-18. Berry Phase and Fidelity in the Dicke model with $A^{2}$ term. https://doi.org/10.1016/j.optcom.2010.04.097

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