Generation of microwave-mechanics and magnon-optics entangled states

Abstract

Quantum entanglement is a key resource for performing quantum computing and building quantum communication networks. By injecting a microwave-optical dual-mode entanglement field into the system, as well as pumping the optical and microwave cavities, and by appropriately choosing the detuning relation between the pumping field and the modes, the paper shows that microwave-mechanics entanglement <i>E<sub>ab</sub></i>and magnon-optics entanglement <i>E<sub>cm</sub></i>can be generated simultaneously in the cavity opto-magnomechanics system, and the entanglement can be in a steady state. Specifically, the model is based on a hybrid quantum system of magnons, where a microwave-light entanglement generated by an optically pulsed superconducting electro-optical device through spontaneous parametric down-conversion process is injected as the intracavity field, and a blue-detuned microwave field is used to excite the magnon modes to produce magnon-phonon entanglement. By interacting with an optomechanical beam splitter and microwave-magnon state-swap interaction, steady microwave-mechanics entanglement <i>E<sub>ab</sub></i> and magnon-optics entanglement<i> E<sub>cm</sub></i> are successfully realized. The entanglement <i>E<sub>ab</sub></i>and <i>E<sub>cm</sub></i> in the system is analyzed using the logarithmic negativity. This paper mainly investigates the effect of several parameters of the system, such as environment temperature, coupling strength and dissipation rate, on the degree of entanglement. In particular, the entanglement <i>E<sub>ab</sub></i> and <i>E<sub>cm</sub></i> generated in this system can exist both simultaneously and individually. Especially when <i>g<sub>am</sub></i>=0, the entanglement <i>E<sub>ab</sub></i> and <i>E<sub>cm</sub></i> still exist. Moreover, directly injecting entangled microwave-light into the system can significantly enhance the robustness of the entanglement against temperature, which will have broad application prospects in quantum information processing in quantum networks and hybrid quantum systems. Notably, the entanglement <i>E<sub>ab</sub></i> and <i>E<sub>cm</sub></i> exist even at a temperature of 1.3K. The implications of our research has potential value for applications in the field of quantum information processing and quantum networks.