Speaker: Dominique Spehner (IUF Grenoble)

Title: Bipartite systems coupled to two baths: Time evolution of Entanglement.

Abstract: I will describe the evolution of entanglement for two qubits
undergoing decoherence processes. These
processes arise by coupling the qubits either to two independent baths
or to a common bath. Our
study relies on some simple markovian models. It will be shown that,
if the dynamics is given by quantum trajectories corresponding to
local measurements on the two independent baths, the mean concurrence
of the qubits decreases exponentially, despite the fact that the
2-qubit density matrix may become separable after a finite time.