Resonant Spin Transmission Mediated by Magnons in a Magnetic Insulator Multilayer Structure
Resonant Spin Transmission Mediated by Magnons in a Magnetic Insulator Multilayer Structure
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DOI：
10.1002/adma.202008555
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发表时间：
2021-04-25
影响因子：
29.4
通讯作者：
Liu, Luqiao
中科院分区：
文献类型：
--
作者：
Fan, Yabin;Finley, Joseph;Liu, Luqiao
在电绝缘的同时，磁性绝缘体可以通过携带自旋电流和激发的自旋波来起到良好的自旋导体的作用。到目前为止，磁性绝缘体在多层异质结构中被用来优化自旋输运或形成磁振子自旋阀以达到控制自旋流动的目的。在这些研究中，相干和非相干磁子在自旋传输中的相应作用仍然是一个被广泛关注的话题。同时，了解绝缘体中与自旋传输相关的潜在机制有助于识别能够进一步提高自旋传输效率的新机制。本文通过研究磁性金属/磁性绝缘体/铂多层膜中的自旋输运，证明了相干磁子可以在磁性绝缘体的磁振子带隙之上有效地转移自旋。特别是驻留自旋波模式可以通过诱导共振磁振子传输来极大地增强自旋流。此外，在磁振子带隙内，观察到由于相干磁子的阻挡，自旋传输被关闭。磁振子的传输增强和滤波效应为调节磁子器件中的自旋流提供了一种有效的方法。
While being electrically insulating, magnetic insulators can behave as good spin conductors by carrying spin current with excited spin waves. So far, magnetic insulators are utilized in multilayer heterostructures for optimizing spin transport or to form magnon spin valves for reaching controls over the spin flow. In these studies, it remains an intensively visited topic as to what the corresponding roles of coherent and incoherent magnons are in the spin transmission. Meanwhile, understanding the underlying mechanism associated with spin transmission in insulators can help to identify new mechanisms that can further improve the spin transport efficiency. Here, by studying spin transport in a magnetic-metal/magnetic-insulator/platinum multilayer, it is demonstrated that coherent magnons can transfer spins efficiently above the magnon bandgap of magnetic insulators. Particularly the standing spin-wave mode can greatly enhance the spin flow by inducing a resonant magnon transmission. Furthermore, within the magnon bandgap, a shutdown of spin transmission due to the blocking of coherent magnons is observed. The demonstrated magnon transmission enhancement and filtering effect provides an efficient method for modulating spin current in magnonic devices.