Generation of squeezed states of magnons and photons based on the Kerr effect in cavity-magnon hybrid system

Based on the magnon Kerr effect, we show how to generate quantum squeezed states of magnons and photons in the cavity–magnon hybrid system. We find that the squeezing of magnons can be successfully induced by the magnon nonlinearity and the larger two-magnon effect strength will be beneficial to achieving the stronger squeezing of magnon. Resorting to the beam-splitter interaction between the magnons and photons, we further show that the squeezing of photons can be also effectively achieved. By properly choosing the system parameters, we demonstrate that the desired direction of the generated squeezing both for magnons and photons can be flexibly switched between orthogonal directions. Our scheme provides an alternative manipulation method to explore the quantum phenomena with nonlinear effects and also has significant potential applications in quantum precision measurement.