Study Of Non-classical Characteristics Of The Atom-cavity-field Interaction

Being carrier of information, photon is getting more and more attention because it has more advantage than electron. We call the new quantum phenomenon that can't be explained by classical theory non-classical feature of cavity field. It has been proved by experiment, that quantum states of cavity field can exhibit three non-classical features, i.e. photon antibunching effect, sub-Poissonian statistics distribution, and squeezed states. In quantum states which have squeezing effect, one quadrature phase may have reduced quantum fluctuations compared with what the relative quadrature phase have in coherent states, which makes it applied widely in optical communication systems, and so on. Therefore, squeezed state of the radiation field is still a central topic in quantum optics. On the one hand, squeezed light can be generated in experiments successfully; on the other, methods of generating highly squeezed states are being searched for intensely.This dissertation is organized as follow:In the first chapter, the concepts of the quantum entangled states, the J-C model, and the squeezed states will be introduced briefly.The second chapter will consider three two-level atoms initially in the GHZ state, then an atom of them will be put into an initially empty cavity and make resonant interaction. After manipulating the atoms outside the cavity, we will consider the change of the squeezed feature of the cavity. Moreover, this result will be generated to n two-level atoms.In the third chapter, three two-level atoms initially in the W state, then two atoms of them will be put into two initially empty cavities and make resonant interaction respectively. After manipulating the atom outside the cavity, we will consider the change of the squeezed feature of the cavities.Our research shows that, it is possible to change the emission properties of the atoms inside the cavities by manipulating the atom outside the cavity.