Research On The Dynamical Properties Of Entanglement In Atom- Cavity-optomechanical Systems

Quantum entanglement is one of the most remarkable features of quantum mechanics and the most difference between quantum mechanics and classical mechanics.Furthermore,quantum entanglement is highly relevant to the fundamental issues of quantum mechanics and plays a central role in quantum information processing.One can even say that,quantum information cannot exit without quantum entanglement.Base on the important application of quantum entanglement in quantum optomechanics,this thesis mainly focuses on the measurement of quantum entanglement,the dynamics of the atom-cavity-optomechanical system,entanglement swapping in Jaynes-Cummings model and atom-cavity-optomechanical system and entanglement swapping in two independent atom-cavity-optomechanical systems.The detailed contents are as follows:The tripartite entanglement between the atom,the field and the oscillating mirror in the atom-cavity-optomechanical system is investigated.The effects of the atomic coherent angle,the spontaneous emission rate of atom,mean photon number and the coupling strength on tripartite entanglement are discussed by the ?-tangle in the ideal case and in the presence of dissipation.The entanglement swapping between atoms and mechanical mode in the Jaynes-Cummings model and atom-cavity-optomechanical system is studied.The influence of the coherent angles of two atoms and the coupling coefficient between the cavity field and the mechanical mode on the entanglement between atoms and mechanical mode is discussed.The dynamics of entanglement between two mechanical modes in two independent atom-cavity-optomechanical systems are investigated.The effects of the coherent angles of two atoms and the coupling coefficients between the cavity field and the mechanical mode on the entanglement between two mechanical modes are examined.The physical mechanism of entanglement control between two mechanical modes is discussed.