利用磁致伸缩效应的腔磁力系统的量子纠缠和纠缠转移

Generation and Transfer of Entanglement Induced by Magnetostriction in Cavity Magnomechanical System

本文提出了一种利用磁致伸缩效应实现两体纠缠和三体纠缠的产生和转移的混合腔磁力系统。该系统由一个微波腔和两个钇铁石榴石(yttrium irongarnet,简称YIG)球组成,磁子模通过磁偶极相互作用耦合到一个腔模。通过调整偏置磁场的方向,使其中一个YIG球产生形变声子模,声子模通过非线性磁致伸缩相互作用与磁子模耦合,在强红失谐微波场驱动下,可以实现两体纠缠的制备,并且纠缠可以在子系统之间转移。此外,本文还证明了克尔(Kerr)非线性可以有效的增强磁子模-腔模-磁子模之间的三体纠缠,并且对环境诱导的退相干具有鲁棒性。该研究结果可为在宏观量子力学和量子信息处理的研究提供参考。

Objective In recent years,various interesting properties in the theory of cavity magnetomechanics have been widely applied and proved in experiments.The combination of subsystems with different characteristics is a good solution for complex and diverse quantum information tasks at this stage.In the field of quantum engineering,achieving optimal performance in quantum communication tasks necessitates robust quantum entanglement to ensure seamless transmission.Nevertheless,environmental factors such as decoherence can lead to the decay or even loss of quantum entanglement.Therefore,it is necessary to adopt additional schemes to enhance quantum entanglement.Method Based on the theory of cavity magnetics,the effects of magnetostrictive nonlinearity and Kerr nonlinearity in cavity magnomechanical system on the quantum correlation between subsystems are studied in this thesis.A hybrid cavity magnomechanical system consisting of a single microwave cavity and two yttrium iron garnet spheres(YIG spheres)is considered.By adjusting the direction of the bias magnetic field and selecting different sizes of YIG spheres,the magnetostriction effect of one YIG sphere is successfully excited,and the self-Kerr effect of the other YIG sphere is preserved.The introduction of two different types of nonlinear effects will bring many interesting properties and more degrees of freedom to cavity magnetomechanical systems,which will help to better control the generation and transfer of quantum entanglement.Results and Discussions In this paper,we have successfully established an asymmetric cavity magnetomechanical system,in which the nonlinearity caused by the magnetostriction effect leads quantum entanglement between the magnon mode and mechanical mode and is transmitted transferred between the subsystems through the interaction between the subsystems.The Kerr nonlinear performance effectively enhances the interaction between the magnon and the microwave cavity,thereby enhancing quantum entanglement in the overall system.In this system,through the flexible adjustment of system parameters,the system can also be converted under different working conditions.Conclusion This paper proposes a method for achieving quantum entanglement and entanglement transfer in cavity magnetomechanical systems using the magnetostriction effect.A hybrid cavity magnetomechanical system consisting of a single microwave cavity and two YIG spheres has been established.The existence of magnetostriction effect can lead the generation and transfer of quantum entanglement.The Kerr effect of YIG spheres can effectively enhance the bipartite entanglement and tripartite entanglement between subsystems.This scheme achieves the generation of quantum entanglement and enhances the robustness of quantum entanglement to environmental temperature,as well as higher tunability.This indicates that the rich nonlinear characteristics in cavity magnomechanical systems can create broad application prospects for quantum information processing and quantum communication.