Entanglement in thermal equilibrium states

ANALÍA ZWICK, OMAR OSENDA AND GUIDO RAGGIO; OMAR OSENDA; GUIDO RAGGIO

Conferencia; IQMBT 13, International Conference on Recent Progress in Many-Body Theories; 2005

We revisit the problem of entanglement of thermal equilibrium states of composite systems. We introduce characteristic, viz. critical, temperatures marking transitions from entanglement to separability or vice versa. We present examples for the various possible thermal entanglement scenarios, resulting from the presence of several transitions, in bipartite qubit/qutrit systems and bipartite sub--systems of larger ones.