Yin Binghui, Yang Mingming, Zeng Xiaoyan, Yan Ming
Department of Physics, Shanghai University, Shanghai 200444, China.
Department of Mathematics, Shanghai University, Shanghai 200444, China.
Materials (Basel). 2022 Sep 5;15(17):6144. doi: 10.3390/ma15176144.
Magnonics is an emerging field in spintronics, aiming at the development of new-concept magnetic devices processing information via the manipulation of spin waves (SWs) in magnetic nanostructures. One of the most popular SW waveguides exploited currently is ferromagnetic nanostrips. Due to quantization caused by the lateral confinements, the dispersion of SWs propagating in a strip is characterized by a multi-branched structure. Consequently, SWs excited in the system involve superpositions of degenerate modes from different branches of the dispersion curves. In this work, we theoretically study the SW branch hybridization effect for two types of excitation methods, either by using a local oscillating magnetic field or a fast-moving field pulse. The former is based on the resonance effect and the latter on the Cherenkov-like emission mechanism. Micromagnetic simulations yield a variety of SW profiles with rather complex structures, which can be well explained by mode superpositions. These results draw attention to the significance of the SW branch hybridization effect when dealing with SWs in nanostrips and provide new aspects for the manipulation of SWs.
磁子学是自旋电子学中的一个新兴领域，旨在开发通过操纵磁性纳米结构中的自旋波（SW）来处理信息的新概念磁性器件。目前使用最广泛的SW波导之一是铁磁纳米带。由于横向限制引起的量子化，在纳米带中传播的SW的色散具有多分支结构的特征。因此，在系统中激发的SW涉及色散曲线不同分支的简并模式的叠加。在这项工作中，我们从理论上研究了两种激发方法的SW分支杂交效应，一种是使用局部振荡磁场，另一种是快速移动的场脉冲。前者基于共振效应，后者基于切伦科夫样发射机制。微磁模拟产生了具有相当复杂结构的各种SW分布，这可以通过模式叠加得到很好的解释。这些结果提请人们注意在处理纳米带中的SW时SW分支杂交效应的重要性，并为SW的操纵提供了新的方面。
