Controllable magnon–magnon entanglement and one-way EPR steering with two cascaded cavities

We propose an alternative scheme for achieving magnon–magnon entanglement and one-way Einstein–Podolsky–Rosen (EPR) steering via the cavity dissipation processes, where two cascaded cavities are respectively coupled to two separated magnon modes of the yttrium iron garnet (YIG) spheres. Based on the quantum theory, the reduced master equation of magnon modes is derived by adiabatically eliminating the cavity variables. The results show that the entanglement and one-way EPR steering of two distant magnons could be obtained and controlled by adequately selecting the physical parameters such as magneto-optical coupling strength, the coupling efficiency of cascaded cavities, and magnon dissipation rate. The remarkable feature of our scheme is that the generated bipartite correlations are insensitive to the dynamical parameter fluctuations. Furthermore, the simplified operation and actual parameters make the scheme more feasible, which may provide a new platform for the study of the macroscopic quantum phenomenon and quantum information processing.