发表机构
School of Physics and Astronomy, Beijing Normal University; Applied Optics Beijing Area Major Laboratory, Beijing Normal University; Key Laboratory of Multiscale Spin Physics (Ministry of Education), Beijing Normal University; Beijing Academy of Quantum Information Sciences（北京师范大学物理与天文学院; 北京师范大学应用光学北京地区重点实验室; 北京师范大学多尺度自旋物理教育部重点实验室; 北京量子信息科学研究院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出带相干反馈的腔磁振子系统方案，利用巴尼特效应实现远程非互易磁振子纠缠，可通过偏置磁场、腔失谐等调控，适度反馈还能提升纠缠临界温度。
AI 中文摘要
我们提出了一种在带有相干反馈的腔磁振子系统中产生和控制远程非互易磁振子-磁振子纠缠的方案。两个微波腔由独立的单模压缩真空场驱动，左腔包含一个旋转的钇铁石榴石（YIG）球，右腔包含一个静止的YIG球。对于固定的旋转方向，反转施加在旋转球上的偏置磁场会改变巴尼特频移的符号，从而产生非互易磁振子-磁振子纠缠。通过调节腔失谐和反馈相位，可在偏置磁场的一个方向上产生纠缠，而在相反方向上纠缠消失，实现完全非互易性。相干反馈在适当的反射率下会增强纠缠，而更强的反馈则会降低纠缠。相对压缩相位提供了额外的控制，在固定总输入光子占据数的情况下，选择合适的不等压缩因子可改善纠缠。在保持压缩输入固定的情况下，适度的反馈还会提高磁振子纠缠的临界温度。这些结果为在腔磁振子系统中制备远程非互易量子关联提供了一种可控方法。
英文摘要
We propose a scheme for generating and controlling remote nonreciprocal magnon--magnon entanglement in a cavity magnonic system with coherent feedback.The two microwave cavities are driven by independent single-mode squeezed vacuum fields, with a rotating YIG sphere in the left cavity and a stationary one in the right cavity. For a fixed rotation direction, reversing the bias magnetic field applied to the rotating sphere changes the sign of the Barnett shift, leading to nonreciprocal magnon--magnon entanglement. By tuning the cavity detuning and feedback phase, entanglement can be generated for one direction of the bias magnetic field while it vanishes for the opposite direction, yielding complete nonreciprocity. Coherent feedback enhances the entanglement at an appropriate reflectivity, whereas stronger feedback can reduce it. The relative squeezing phase provides additional control, and an appropriate choice of unequal squeezing factors improves the entanglement at fixed total input photon occupation. With the squeezed inputs kept fixed, moderate feedback also increases the critical temperature for magnon entanglement.Our results provide a controllable approach to preparing remote nonreciprocal quantum correlations in cavity magnonic systems.
Comments8 Pages, 8 figures
