Multipartite entanglement and one-way steering in magnon frequency comb

We theoretically demonstrate that multipartite entanglement and one-way Einstein–Podolsky–Rosen (EPR) steering in a magnon frequency comb (MFC) can be generated in a hybrid magnon–skyrmion system. When the system is driven by two microwave fields at the magnonic whispering gallery mode (mWGM) and the skyrmion, the skyrmion can be simultaneously entangled with three magnon modes of the MFC and the entanglement of the first-order magnon pair in the MFC also appears. The results show that the perfect one-way steering between the skyrmion and the three magnons can be obtained. Interestingly, the steering direction can be manipulated by controlling the amplitudes of two drive fields, which provides flexibility in controlling the asymmetry of the EPR steering and may well have practical applications. Moreover, the genuine tripartite entanglement among the skyrmion and the first-order magnon pair can be achieved with appropriate parameters in the steady state. Our work exhibits that the MFC has great potential in preparing multi-mode entanglement resources, with promising applications in quantum communication.