English

Superradiant Phase Transitions and the Standard Description of Circuit QED

Mesoscale and Nanoscale Physics 2011-09-20 v1 Quantum Physics

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.

Keywords

Cite

@article{arxiv.1103.4639,
  title  = {Superradiant Phase Transitions and the Standard Description of Circuit QED},
  author = {Oliver Viehmann and Jan von Delft and Florian Marquardt},
  journal= {arXiv preprint arXiv:1103.4639},
  year   = {2011}
}

Comments

4+6 pages, 3+1 figures