Enhanced maximum entanglement between two microwave fields in the cavity magnomechanics with an optical parametric amplifier

We consider a cavity magnomechanical (CMM) system with an optical parametric amplifier (OPA), which contains two microwave (MW) cavities, a magnon mode, and a phonon mode. The magnon mode interacts simultaneously with the two MW cavities and phonon mode via the magnetic dipole and magnetostrictive interactions, respectively. This paper investigates how the presence of an OPA inside the CMM system can improve the steady-state entanglement of the two MW cavities. Our findings show that with the presence of the OPA, the two MW cavities fields are squeezed which leads to a strong bipartite entanglement between them when both MW cavities resonate with the magnon-drive frequency, and that the entanglement is more resistant to the thermal effects than the system without the OPA.