Once more on the equivalence between quantum phase transition phenomena in radiation-matter and magnetic systems
Quantum Physics
2007-05-23 v1
Abstract
In answer to the replies of Reslen {\it et al} [arXiv: quant-ph/0507164 (2005)], and Liberti and Zaffino [arXiv:cond-mat/0507019, (2005)], we comment once more on the temperature-dependent effective Hamiltonians for the Dicke model derived by them in [Europhys. Lett., {\bf 69} (2005) 8] and [Eur. Phys. J., {\bf 44} (2005) 535], respectively. These approximate Hamiltonians cannot be correct for any finite nonzero temperature because they both violate a rigorous result. The fact that the Dicke model belongs to the universality class of, and its thermodynamics is described by the infinitely coordinated transverse-field XY model is known for more than 30 years.
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Cite
@article{arxiv.quant-ph/0508039,
title = {Once more on the equivalence between quantum phase transition phenomena in radiation-matter and magnetic systems},
author = {J. G. Brankov and N. S. Tonchev and V. A. Zagrebnov},
journal= {arXiv preprint arXiv:quant-ph/0508039},
year = {2007}
}
Comments
3 pages