Entangled States And Quantum States Of Atoms Can Be Purified,

In chapter one we propose a scheme to generate maximally entangled states of two trapped atomic groups via the interaction between the single-mode cavity field and the trapped atomic groups. The effects of atom decay on the entanglement preparation are presented and discussed. The thermal entanglement and its critical temperature are also presented. The distillability criterion is given in terms of Kraus operators in chapter two. By making use of the criterion, we discuss the time evolution of distillability for and systems that initially in maximally entanglement states. There are two distinguished processes, dissipation and decoherence, which may destroy the distillability. We discuss the effects of those processes on distillability in details.