Preparation Of Particle Entanglement In Cavity QED

Entanglement is recognized nowdays as a key ingredient for fundamental tests of quantum nonlocal and as a basic resource of quantum information transmission or processing. the preparation of entanglement has been the theme of the quantum processing. Recently a lots of schemes for the prepraration of quantum entanglement has been presented based on some different models. The interaction of the quantized cavity field with the Rydberg atoms is ideal for generating entangled states or for quantum information processing. In the paper,we present the scheme to generate a maximally entangled state of multiple separate modes based on the resonant atom-cavity interaction in microwave cavity QED and a scheme to generate a maximally entangled state of two multi-level atoms with a nonresonant cavity by cavity assisted collisions.In chapter 1. We introduce the quantum theory base of entanglement, then we introduce the concept of entanglement and the development of quantum entanglement, the application of entanglement for quantum information processing and the last development of the generation of the entangled state.In chapter 2. We research the preparation of multiparticle entanglement based on Jaunes-Cumming model. We present a scheme to generate a maximally entangled state of two separate cavity modes, by using the resonant interaction of a three-level atom and two separate cavity modes, using classical field and selecting the interaction time. Via this scheme,we can generalize maximally entangled states of multiple separate field modes.In chapter 3. We present a scheme to generate a maximally entangled state of two multi-level atoms with a nonresonant cavity by cavity-assisted collisions. It is the advantage of this scheme that since the cavity field is only virtually excited ,no information will be transferred from the atoms to the cavity, this scheme is insensitive to both the cavity decay and the thermal field. then we study the generation of three multi-level atoms entangled sate based on the resonant interaction the atom and the cavity field.