Nonreciprocal Strong Mechanical Squeezing Based on the Kerr Effect in Cavity‐Magnon Optomechanical System

Abstract In this study, a scheme is proposed to generate nonreciprocal strong mechanical squeezing in a cavity‐magnon optomechanical system based on the Kerr nonlinearity of the yttrium‐iron garnet (YIG) sphere. It is found that the magnon squeezing can be directly produced by the Kerr effect and it can induce strong mechanical squeezing through the squeezing transfer achieved by the cavity‐magnon interaction and the optomechanical interaction. The results further show that the mechanical mode coupled to the cavity can achieve squeezing effect in the selected magnetic field direction, but not in the opposite one. Moreover, by properly adjusting the magnon effective detuning and the Kerr effect strength, the degree of squeezing of the mechanical mode can even beyond the 3‐dB limit, and the optimal conditions for generating stronger squeezing are obtained. This work has important applications in the nonreciprocal quantum devices, quantum information processing, and quantum precision measurement.