Brazilian Journal of Physics
versão impressa ISSN 0103-9733
ZANDER, C.; PLASTINO, A. e PLASTINO, A. R.. Quantum entanglement in a many-body system exhibiting multiple quantum phase transitions. Braz. J. Phys. [online]. 2009, vol.39, n.2a, pp. 464-467. ISSN 0103-9733. http://dx.doi.org/10.1590/S0103-97332009000400022.
We investigate the quantum entanglement-related features of the many-body model of Plastino and Moszkowski [N. Cimento 47 (1978) 470]. This is an exactly solvable N-body, SU2 two-level model exhibiting several quantum phase transitions. We show that these transitions happen to be also entanglement-transitions associated with different many-body Dicke states. The main properties of the model considered here make it particularly well suited to study, by recourse to exact analytical computations, some connections between quantum phase transitions and quantum entanglement-theory.
Palavras-chave : Quantum phase transitions; Many body systems.