Robust Bipartite Entanglement in an Optomechanical System Assisted by Three Level Laser

Abstract

In this thesis, we theoretically analyzed the bipartite entanglement of an optome chanical system for single mode light produced by three level lasers. To this aim, we constructed the model and Hamiltonian of system. While, the system consists of one fixed mirror and one movable mirror and a degenerate three level atoms placed between them. Thus, the cavity mode is driven by a laser field and the interaction of three level atoms and a laser field is analyzed. Accordingly, the dynamics of the system can be obtained by using the nonlinear quantum Langevin equations and linearization approximation. Under the linearization approximation, the bipartite entanglement is quantified through logarithmic negativity. Accordingly, our results showed that the introduction of three level atoms makes the entanglement more ro bust. Interestingly, we showed that the effects of atom-field coupling, the internal energy of atoms and atomic detuning have great contribution for the enhancement of the stationary continuous variable entanglement. Thus, when three level atoms are added inside a cavity, the optomechanical coupling and the bipartite entangle ment is enhanced. Such entanglements results may have spectacular contribution for constructing long-distance quantum communication network and technologies