Enhancement of Bipartite Entanglement in Cavity Magnomechanical Systems Assisted by an Optical Parametric Amplifier

Abstract

In this thesis, we studied the enhancement of quantum entanglement induced by optical parametric amplifiers in a hybrid cavity magnomechanical system. The hybrid configuration we investigated involves magnons, cavity microwave photons, and phonons. We constructed the model and Hamiltonian to describe our system. The system’s dynamics were determined using the nonlinear quantum Langevin equations and the linearization approximation. In this framework, the bipartite entanglements were evaluated through logarithmic negativity. It turned out that the bipartite entanglements were enhanced when an optical parametric amplifier was present. In the same way, OPA improved entanglement’s resistance to temperature. The relaxation of the prerequisite for strong magnon-phonon coupling, which was required in the absence of OPA to produce cavity-magnon entanglement, was another important effect of the OPA. Furthermore, in comparison to the system in which the optical parametric amplifier (OPA) was absent, the inclusion of the OPA not only strengthened the entanglement but also expanded its domain over a larger range of detunings. We believe that the technique that was given is a step towards realizing robust quantum entanglement with the available technology.