Harnessing the spin-momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi₂Se₃/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi₂Se₃ film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG. Temperature-dependent ferromagnetic resonance of Bi₂Se₃/YIG reveals signatures of the magnetic proximity effect of T_C as high as 180 K, an emerging low-temperature perpendicular magnetic anisotropy competing the high-temperature IMA, and an increasing exchange effective field of YIG steadily increasing toward low temperature. Our study sheds light on the effects of topological insulators on magnetization dynamics, essential for the development of topological insulator-based spintronic devices.

中文翻译：

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Bi2Se3 /钇铁石榴石异质结构中的强交换耦合和表面状态调制的磁化动力学。

利用磁性材料来控制拓扑表面状态的自旋动量锁定是实现新型基于拓扑绝缘体的设备的第一步。在这里，我们报告Bi ₂ Se ₃ /钇铁石榴石（YIG）双层中的强界面耦合表现为大的界面平面磁各向异性（IMA）和铁磁共振探测的阻尼增强。当Bi ₂ Se ₃薄膜接近其二维极限时，界面IMA和阻尼增强达到最大值，表明拓扑表面状态在YIG的磁化动力学中起着重要作用。Bi ₂ Se _3的随温度变化的铁磁共振/ YIG揭示了T _C高达180 K的磁邻近效应的特征，与高温IMA竞争的新兴的低温垂直磁各向异性，以及向低温稳定增长的YIG交换有效场的增加。我们的研究揭示了拓扑绝缘子对磁化动力学的影响，这对于基于拓扑绝缘子的自旋电子器件的发展至关重要。