Entanglement enhancement through magnon squeezing and optical parametric amplifier in cavity magnomechanics

Abstract

We consider a cavity magnomechanical (CMM) system comprising magnon, cavity, and phonon modes. The coupling between the magnon and cavity, as well as between magnon and phonon, is mediated by the magnetic-dipole interaction and magnetostrictive interaction, respectively. By incorporating the optical parametric amplifier (OPA) and magnon squeezing mechanisms induced by the magnon self-Kerr nonlinearity, we observe a significant enhancement in entanglement between magnon-cavity, cavity-phonon, as well as tripartite entanglement, compared to the case where OPA and magnon squeezing are not introduced. We also explore the adverse effect of the thermal bath on the mechanical mode, specifically concerning the generation of magnon-phonon entanglement. Additionally, the presence of both magnon squeezing and OPA has been shown to play a crucial role in enhancing the robustness of entanglement against thermal effects compared to the cases when OPA is applied alone or when magnon squeezing is used alone. Here, the entanglement between the magnon and cavity persists up to a temperature of 284 mK, higher than previously observed values. The current CMM system shows promise for use in quantum tasks where it is necessary to enhance entanglement.