Entanglement and Entropy in a Spin-Boson Quantum Phase Transition
Abstract
We investigate the entanglement properties of an ensemble of atoms interacting with a single bosonic field mode via the Dicke (superradiance) Hamiltonian. The model exhibits a quantum phase transition and a well-understood thermodynamic limit, allowing the identification of both quantum and semi-classical many-body features in the behaviour of the entanglement. We consider the entanglement between the atoms and the field, an investigation initiated in [N. Lambert, C. Emary and T. Brandes, Phys. Rev. Lett. {\bf 92}, %073602 (2004)]. In the thermodynamic limit, we give exact results for all entanglement partitions and observe a logarithmic divergence of the atom-field entanglement, and discontinuities in the average linear entropy.
Cite
@article{arxiv.quant-ph/0405109,
title = {Entanglement and Entropy in a Spin-Boson Quantum Phase Transition},
author = {N. Lambert and C. Emary and T. Brandes},
journal= {arXiv preprint arXiv:quant-ph/0405109},
year = {2009}
}
Comments
9 pages, 3 figures. Significantly Shortened. Removed concurrence section, multipartite section significantly changed. 14 pages, 4 figures, submitted to PRA