Enhanced tripartite magnon-phonon entanglement via orbital angular momentum exchange

In this paper, we propose a scheme to prepare macroscopic tripartite magnon-phonon entanglement via orbital angular momentum (OAM) exchange. By placing two magnons into a cascade rotational cavity optomechanical system, we explore that the optimal tripartite magnon-phonon entanglement is achievable when one magnon mode is tuned to be resonant with the red sideband while the other one with the blue sideband in cavity-magnon dispersive regimes. On the other hand, it is found that the scheme for generating bipartite magnon-magnon entanglement is distinct from tripartite entanglement, wherein the entanglement is initially prepared between the cavity modes and then transferred to magnon modes when cavity-magnon resonant conditions are satisfied. Furthermore, we demonstrate that the tripartite and bipartite entanglements are optimal by taking moderate coupling strengths. The present scheme provides a method to obtain genuine multipartite entanglement, which may find potential applications for constructing a macroscopic quantum network.