发表机构
Huazhong University of Science and Technology; V. G. Baryakhtar Institute of Magnetism of the NAS of Ukraine; Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau; University of Vienna（华中科技大学; 乌克兰国家科学院巴里亚赫塔尔磁学研究所; 莱茵兰-普法尔茨技术大学凯泽斯劳滕-兰道分校; 维也纳大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种交换介导的定向耦合器，用磁修饰YIG间隔层替代非磁性间隙，实现约100纳米波长自旋波98%的功率传输，克服了偶极耦合器的短波长限制，为高集成磁振子电路提供途径。
AI 中文摘要
缩小磁振子电路尺寸并提高其处理速度需要波长越来越短的自旋波。然而，传统定向耦合器依赖于空间分离波导之间的动态偶极相互作用，这种作用在交换主导区域会迅速减弱。因此，其耦合长度随自旋波波长减小而增加，限制了器件的进一步小型化。在此，我们通过将两个波导之间的非磁性间隙替换为磁修饰的YIG间隔层，引入了一种交换介导的定向耦合器。该间隔层提供了连续的交换路径，并在大波数下保持对称与反对称模式之间的分裂。我们建立了一个解析模型来描述这一机制，并通过微磁模拟对其进行了验证。基于这一概念，我们设计了一个无需弯曲接入波导的直耦合器，其占地面积仅为400纳米×30纳米。对于约100纳米波长的自旋波，该器件将约98%的归一化输出功率传输至目标波导。即使间隔层的阻尼显著增加，其性能也几乎保持不变。这些结果克服了偶极耦合器的短波长限制，为高度集成的磁振子信息处理电路提供了途径。
英文摘要
Miniaturizing magnonic circuits and increasing their processing speed require spin waves with progressively shorter wavelengths. However, conventional directional couplers rely on the dynamic dipolar interaction between spatially separated waveguides, which rapidly weakens in the exchange-dominated regime. As a result, their coupling length increases as the spin-wave wavelength decreases, limiting further device miniaturization. Here, we introduce an exchange-mediated directional coupler by replacing the nonmagnetic gap between two waveguides with a magnetically modified YIG spacer. The spacer provides a continuous exchange pathway and preserves the splitting between the symmetric and antisymmetric modes at large wavenumbers. We develop an analytical model to describe this mechanism and verify it using micromagnetic simulations. Based on this concept, we design a straight coupler without curved access waveguides, with a footprint of only 400 nm * 30 nm. For a spin-wave wavelength of approximately 100 nm, the device transfers approximately 98% of the normalized output power to the target waveguide. Its performance remains nearly unchanged even when the damping of the spacer is strongly increased. These results overcome the short-wavelength limitation of dipolar couplers and provide a route toward highly integrated magnonic circuits for information processing.
Comments23 pages, 4 figures
