Research On Entanglement Properties Of The Atom System Interacting With Field Under The Dressed-state Representation

The German scientist Max Planck first put forward light quantum hypothesis in the early twentieth century, and quantum mechanics has been a century history. As unceasing understanding and study of quantum mechanics, people can find some of the basic principles and the unique nature which can be well applied to information subject in quantum mechanics.Based on the important applications of quantum entanglement in the quantum information processing, this thesis is mainly to study quantum entanglement, the theory of dressed-state, quantum entanglement of the system about atoms interacting with the environment, quantum entanglement and entropy compression of the system about atoms interacting with the field under the dressed-state representation. The specific work is:Two interacting qubits coupled to Markovian environment and non-Markovian environment has been considered. The entanglement dynamics of two interacting qubits under the influence of environment is examined by making use of the linear entropy. The effect of the strength of the dipole-dipole interaction and the detuning between the center frequency of the environment and the qubit transition frequency on the time evolution of entanglement is discussed.The dynamics of the entanglement and entropy squeezing of the two-level atom driven by classical fields interacting with field by employing the dressed-state representation is examined. The influence of the photon number of Fock state, coupling coefficient of atoms and the classical driving field, and the detuning between the atomic transition frequency and the frequency of classical driving field on the entanglement and entropy squeezing of the atom is analyzed. The relationship between atomic linear entropy and entropy squeezing of the two-level atom driven by classical fields interacting with field by employing the dressed-state representation is discussed.The dynamics of the entanglement of the two qubits system interacting with vacuum field by employing the dressed-state representation is examined,and two qubits are driven by classical fields. The influence of the initial entanglement degree of two qubits, the coupling strength of atoms and the classical field and the detuning between the atomic transition frequency and the frequency of classical field on the entanglement and atomic linear entropy is analyzed.