Study On Quantum Interference Effect In A Multi-level Atomic System

Recently, Quantum interference in quantum optics has been discussed extensively.many interesting phenomena have been observed due to quantum interference among multi-channels in multilevel atomic systems. On the other hand, as a new branch of science and technology, quantum manipulation is very active these years. Its development may change computer, medical science, chemistry and life sciences, etc. thoroughly, thus make human life change tremendously. At present, the study focus of quantum manipulation is physical realization, and the research of the quantum control system is also mainly in the stage of theoretical exploring. In this thesis, by means of quantum optics theory, we have intensively investigated the problem theoretically, and a series of meaningful results are obtained.Quantum interference is very different from the classical interference, which breaks through the traditional bottleneck while leading into the superposition principle in quantum mechanics, it makes important progress in many fields especially in quantum information, quantum communication encryption and light quantum computer, etc. This thesis is based on the National Natural Science Foundation of China "nonlinear effects at the low light levels" and "single photo laser", we have further studied many kinds of quantum manipulation phenomena on the basis of quantum interference. The key points of this thesis are presented as follows:1. Overview the tendency of the quantum interference and quantum manipulation.2. Making an analysis of relevant research approaches, tool foundations of the theory included theory of density matrix, Semi-classical Theory and quantum theory and several kinds of basic representation.3. In the system of a tripod-type four-level atom system interacting with three light fields. Under the effect of quantum interference, electromagnetic induced transparence(EIT) and optical switching phenomena is researched.4. The quantum mechanics system of interacting between double∧type four-lever atoms and four light fields is studied, investigates how to realize quantum effect manipulation under double cooperating drive light fields. 5. The quantum mechanics system with interacting between Y, quasi-∧type four-lever atoms and multi-mode light fields is discussed, under the mechanism of quantum interference, the left handedness effect happens.6. At last,the summary of the paper is presented.This project is supported by the National Natural Science Foundation of China (Grant No.10464002,No.60768001)...