Magnon-rotation enhanced nonreciprocity of multipartite entanglement in a magnomechanical system

Nonreciprocal physics is attracting significant interest in quantum information processing. In this work, we propose a scheme to investigate the nonreciprocity of bi- and tripartite entanglement and generate squeezed states in a magnomechanical system. This is achieved through the Barnett effect, which originates from the rotation of the first magnon mode. The system consists of two YIG spheres, each supporting a magnon mode that represents collective spin motion, positioned inside a microwave cavity (MC). We show that the Barnett effect enhances entanglement under thermal effects and generates squeezed states for the two magnon modes and the photon mode. Moreover, we show that magnon-magnon coupling enhances entanglement between different two modes.