Investigations On Implementation Of Quantum Logic Gates And Quantum Teleportation

Quantum information theory is a magnificent achievement of the application of quantum mechanics in information science. It is a rapidly growing brand-new cross science subject with a wide and profound future application field. Quantum information mainly includes quantum computation and quantum communication. Recent years, a great deal has been written and a lot of experiments have been performed. In addition, quantum information can develop a lot of new information functions that classical information doesn't have. Therefore, quantum information will inaugurate a new way for the development of information. In addition, it is helpful for the research on basic problems of quantum mechanics itself.Quantum states are quantum carriers of quantum information, so disposal of quantum information virtually is preparation and manipulation of diversified quantum states. In this thesis, we present a number of schemes for implementing basic quantum logic gate, generating entanglement states of cavity field and teleporting a Schrodinger Cat state .This is shown as follow:1. An alternative scheme is proposed to implement some basic quantum logic gates, using the method based on a quantum system, which is composed of the one-dimensional trapped-ion motion and a single cavity field mode. In the scheme, compute basis is composed by the internal ionic state and the cavity state by the connection of motional state. Furthermore, we considered the case that Lamb-Dicke limit is not required.2. A V-type three-level atom is sent through two or more single-mode cavities filled with Fock state or squeezed coherent state respectively, the system is entangled via the atom-cavity Raman interaction. Then detection the atom leaves the cavity system in a Bell-type entangled state or squeezed coherent entangled state respectively. This is helpful for the study about preparation of entangled state and teleportation in quantum information.3. A simple scheme is presented for the teleportation of a Schrodinger cat state via the Raman interaction of A -type three-level atom with two cavity- fields. In the scheme, the entangled state of atom and cavity are used as the quantum channel. The result shows that our scheme is easily performed compared withthe other corresponding schemes.Our results may be useful in the implementation of quantum logic gates, preparation of entangled state and teleportation of quantum state.