Implementing Quantum State Preparation And Teleportation Via Cavity QED

Quantum information is an interesting new subject, which is a combination of quantum mechanics and information science. It makes quantum state information carrier, and manages quantum information by state preparation and manipulation. It consists of quantum communication and quantum computation. So for, there are many physical systems which can carry out quantum communication and quantum computation. Among them, Cavity Quantum Electrodynamics (cavity QED) is investigated earlier and deemed to the most promising one.Cavity QED is one of the key physical systems to implement quantum computer and quantum communication network. The idea is to trap several atoms in a small high finesse optical cavity. Quantum information can be stored in the internal states of atoms. All the trapped atoms in cavity are coupled to the field. It results in interaction among atoms. When the atoms are closed in the high quality cavity, the effect of decoherence between atom-photon system and ambiance can be restrained greatly. So the atom-photon system will keep well coherence during the interaction. In some modern experiments, the well coherence of CQED experiment make itself an ideal proving ground in quantum information field, which include quantum communication , quantum computation and quantum control. In this paper, we discuss some applications of cavity QED with the main work as follows:(1) Implementing quantum state preparation. The scheme for preparation of the maximal entangled states for many (?) -type three-level atoms in athermal cavity are proposed. Multi-atom entanglement not only can be used to validate the quantum nonlocality, but also is basic to realize quantum computer. In order to cut down the requirement on the quality factor of the cavity, the transition frequency between states is highly detuned from the cavity frequency and the cavity is only virtually excited. In the large...