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arXiv · 1103.4639

Superradiant Phase Transitions and the Standard Description of Circuit QED

Oliver Viehmann·Jan von Delft·Florian Marquardt
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Abstract

We investigate the equilibrium behaviour of a superconducting circuit QED system containing a large number of artificial atoms. It is shown that the currently accepted standard description of circuit QED via an effective model fails in an important aspect: it predicts the possibility of a superradiant quantum phase transition, even though a full microscopic treatment reveals that a no-go theorem for such phase transitions known from cavity QED applies to circuit QED systems as well. We generalize the no-go theorem to the case of (artificial) atoms with many energy levels and thus make it more applicable for realistic cavity or circuit QED systems.

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Oliver Viehmann, Jan von Delft, Florian Marquardt. 2011-03-23. Superradiant Phase Transitions and the Standard Description of Circuit QED. https://doi.org/10.1103/physrevlett.107.113602

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