Generation of bipartite entanglement in a dissipative cavity magnomechanical system

Abstract

Abstract In this work, we employ logarithmic negativity to rigorously investigate bipartite entanglements in a lossy cavity magnomechanical system incorporating both photon and magnon Kerr nonlinearities. The system comprises two optical cavity modes, two yttrium-iron-garnet (YIG) spheres, which support magnon and phonon modes, and two electromagnetic fields that drive the magnons. Through numerical simulations, we systematically examine the influence of significant parameters, including photon-magnon and phonon-magnon coupling strengths, dissipation rates, Kerr nonlinearities, environmental temperatures, and normalized detuning on the bipartite entanglements between distinct subsystems. Our findings reveal that the amounts of bipartite entanglements can be precisely tuned by optimizing these parameters. Specifically, increasing either dissipation or Kerr nonlinearity diminishes the maximum values of entanglement. Furthermore, when the magnomechanical coupling is stronger, the entanglement becomes more robust and can endure across a broader spectrum of temperatures. Moreover, the entanglement generated within the subsystems demonstrates remarkable robustness against environmental temperature. Additionally, the maximum survival temperature of bipartite entanglements varies across different entangled pairs, and can be effectively controlled by the optical-magnon coupling strength. Notably, entanglement between subsystems persists even at cryogenic temperatures.