Modulation Of The Non-classical Characteristics Of Quantum System Induced By The Time-varying Frequency Of Radiation Fields

In the context of quantum optics, the study of quantum features for the interaction between optical fields and atoms has attracted much attention. It is one of the most important contents of quantum optics to study the dynamics and the non-classical features of optical fields and atoms in the Jaynes-Cummings interaction model. In this thesis, the dynamical features of time-varying-frequency radiation field interacting with a two-level atom have been studied by using the quantum theory and the numerical simulation method. A series of significant results are obtained.In chapter 1, the elementary theories of the interaction between optical fields and atoms were introduced, such as the history of quantum optics, quantization of radiation fields, several kinds of non-classical states and an important interaction model (Janynes-Cummings model).In chapter 2, we studied the interaction Hamiltonian of the two-level atom and a single-mode radiation field, and tried to find the factors that determine the coupling coefficient between cavity modes and atoms. By introducing the vibration mechanism of one cavity mirror, we first got the connection between the frequency of the cavity mode and the vibration of the cavity mirror, and then we found the relationship between the time-varying function of the mode frequency and that of the volume of the cavity. Finally, we got the exact relationship between the time-varying function of the mode frequency and the coupling coefficient between cavity modes field and atoms.In chapter 3, the effect of the amplitude-squared squeezing of the time-varying-frequency field interacting with a two-level atom is studied by using the numerical method. Here, the field is in binomial state, and the interaction can be described by a generalized J-C model under rotating wave approximation. The results showed that the depth and the period of the amplitude-squared squeezing effect of optical field are determined by the time-dependent frequency variance of the optical field. In chapter 4, we summarized the main results and made an outlook for our further investigations in the near future.