  We present a novel cavity opto-magno-mechanical hybrid system to generate
entanglements among multiple quantum carriers, such as magnons, mechanical
resonators, and cavity photons in both the optical and microwave domains. Two
Yttrium iron garnet (YIG) spheres are embedded in two separate microwave
cavities which are joined by a communal mechanical resonator. Because the
microwave cavities are separate, the ferromagnetic resonate frequencies of two
YIG spheres can be tuned independently, as well as the cavity frequencies. We
show that entanglement can be achieved with experimentally reachable
parameters. The entanglement is robust against environmental thermal noise,
owing to the mechanical cooling process achieved by the optical cavity. The
maximum entanglement among different carriers is achieved by optimizing the
parameters of the system. The individual tunability of the separated cavities
allows us to independently control the entanglement properties of different
subsystems and establish quantum channels with different entanglement
properties in one system. This work could provide promising applications in
quantum metrology and quantum information tasks.
