Enhanced entanglement and steering in [formula omitted] -symmetric cavity magnomechanics

Abstract

We study creation of entanglement and quantum steering in a parity-time- (PT-) symmetric cavity magnomechanical system. There are photon–magnon coupling and phonon–magnon coupling in this system. By introducing a gain cavity mode, a PT-symmetric Hamiltonian of the system is obtained. We find that bipartite entanglement and magnon→phonon steering in PT-symmetry system (gain–loss system) are significantly enhanced versus the case in the conventional cavity magnomechanical system (loss–loss system). Moreover, the magnon→phonon one-way-like quantum steering can be realized in unbroken-PT-symmetry regime. The boundary of stability is demonstrated and it shows that the gain–loss system becomes more stable with respect to the conventional loss–loss system under the parameters we consider. This work opens up a route to explore the characteristics of quantum entanglement and steering in magnomechanical systems, which might have potential applications in quantum state engineering and quantum information.