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Phase Transitions in Generalised Spin-Boson (Dicke) Models

Clive Emary·Tobias Brandes
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Abstract

We consider a class of generalised single mode Dicke Hamiltonians with arbitrary boson coupling in the pseudo-spin $x$-$z$ plane. We find exact solutions in the thermodynamic, large-spin limit as a function of the coupling angle, which allows us to continuously move between the simple dephasing and the original Dicke Hamiltonians. Only in the latter case (orthogonal static and fluctuating couplings), does the parity-symmetry induced quantum phase transition occur.

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Clive Emary, Tobias Brandes. 2004-01-07. Phase Transitions in Generalised Spin-Boson (Dicke) Models. https://doi.org/10.1103/physreva.69.053804

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