Modulating nonreciprocal transmission in levitated magnomechanical systems

In this paper, we propose a model of a dual cavity magnomechanical system with two levitated yttrium iron garnet spheres to investigate nonreciprocal transmission of a microwave field. We use an external Coulomb force to bias the steady-state position of the sphere levitated in each microwave cavity, thereby establishing an independent and controllable effective couplings between the cavity modes and the magnon modes. This can break the symmetry of the system and serve as the basis for nonreciprocal transmission in this system. We demonstrated how to achieve the system nonreciprocity with an extremely high isolation ratio and flexible controllability by appropriately selecting the suspended positions of the levitated spheres, which are related to the external bias forces. We also analyze in detail the influence of the cavity detunings and the driving power on the bias-force-induced nonreciprocity. Our study provides an effective approach to manipulating flexibly nonreciprocal transmission of a microwave field and may have potential implications for the development of future nonreciprocal transmission devices.