Simultaneous cooling of two levitated macromagnets in cavity magnomechanical system

Cooling the motion of multiple isolated, levitated particles has the potential to explore the limits of quantum mechanics in a new mass regime. This technique not only serves as a foundation for examining macroscopic quantum states and building high-precision sensors, but also crucial for overcoming detrimental cross-coupling and decoherence effects in multimode systems. In this paper, we studied that the center-of-mass modes of multi-magnons can be simultaneously cooled to their quantum ground states. Our scheme is realized by adjusting the coupling position of the particle to compensate for the reduction in coupling strength due to magnonic excitations. Additionally, we find that the cooling rate of a magnon is influenced by its own coupling strength and the effective detuning. The numerical simulation results indicate that the lowest phonon occupancy can be cooled to less than 1 simultaneously.