Generating Squeezing and Enhancing Entanglement Based on Magnon‐Induced Brillouin Light Scattering via Pump Modulation

ABSTRACT

We study a dissipative opto‐magnomechanical system implemented using a yttrium iron garnet (YIG) sphere, which supports a magnon mode and two optical whispering‐gallery modes coupled via magnon‐induced Brillouin scattering. Besides, another mechanical mode is considered, which interacts with the optical and magnon modes through radiation pressure and magnetostriction, respectively. This hybrid system is under combined optical driving for the optical modes and microwave driving for the magnon mode and the amplitude of the microwave field is periodically modulated. We apply different parametric approximations by strongly driving one of the optical modes for preparing squeezing and entangled states, respectively. When the classical driving fields are red‐detuned, strong mechanical squeezing beyond the 3‐dB limit is achieved, along with simultaneous squeezing of all three modes. In addition, when the microwave field is red‐detuned and the optical laser is blue‐detuned, significant bipartite and tripartite entanglement is generated. These quantum entanglements are markedly enhanced by periodic modulation compared to the non‐modulated case. The proposed configurations exhibit strong robustness against system dissipation and environmental temperature, suggesting their potential as quantum resources for metrology and information processing applications.