Study On The Properties Of Evolution Of Light-Field Quantum-Entropy In The System Of Q-mode Light-Field Interacting With The Two Identical Two-Level Atoms

In this thesis, the complete quantum theory and the numerical calculating method are utilized firstly to study the properties of time evolution of field quantum-entropy of multimode light-field in the system of q-mode light-field interacting with two identical two-level atoms coupled by dipole-dipole through any NΣ-photon process with any Nj-degree degenerate. Then the formulas for calculating field quantum-entropy of light-field in the system of light-field interacting with atoms mentioned above are given under different initial conditions that are satisfied by multimode light-field and the two coupled atoms respectively, the Matlab graphical programme of computer is used to make the numerical calculating for the theoretical results in detail, and a series of the new results and conclusions are therefore obtained. It is found as follows:(1) The properties of time evolution of field quantum-entropy of light-field are researched in the system of multimode light-field which is laid in multimode Fock state at the initial time interacting with two identical two-level atoms coupled by dipole-dipole which are laid in one of the four kinds of different atomic states such as + , + , , , +, and ,+ at the initial time respectively. And the main characteristic of time evolution of field quantum-entropy of light-field above is thereby revealed by using the numerical calculation and analyses.(2) The properties of time evolution of field quantum-entropy of light-field are researched in the system of multimode light-field which is laid in multimode coherent state at the initial time interacting with two identical two-level atoms coupled by dipole-dipole which are laid in the double excited state + , + at the initial time. The influences of different parameters of the system mentioned upon the properties of time evolution of field quantum-entropy of light-field are analyzed in detail by utilizing the numerical calculations, and some new results and conclusions are further obtained.(3) The properties of time evolution of field quantum-entropy of light-field are studied in the system of multimode number-state light-field interacting with two identical two-level atoms coupled by dipole-dipole which are laid in one of the four kinds of different Bell states evolution of field quantum-entropy of light-field are analyzed in detail under the different conditions mentioned above, and its physical essence is further revealed.(4) The properties of time evolution of field quantum-entropy of light-field are also studied in the system of multimode coherent state light-field interacting with two identical two-level atoms coupled by dipole-dipole which are laid in one of the four kinds of different Bell states at the initial time respectively. By applying numerical calculations, the properties of time evolution of field quantum-entropy of light-field are studied under the above conditions, and its general characteristics are revealed too.It is pointed out that the research results in this thesis are of great important values for applications in the regime of quantum informatics such as quantum communication, light-quanta communication, and so forth.