講演情報
[14p-K303-5]Asymmetric attenuation of surface acoustic waves by magnetic layers with compositional gradients
〇佐藤 駿輝1、芳井 崇悟1、大島 諒1、白石 誠司1 (1.京大工)
キーワード：
Spintronics、Surface acoustic wave
Surface acoustic wave (SAW) is mechanical vibrations that propagate locally on a solid surface and is used in devices such as high-performance filters. In the context of spintronics, SAWs interact with magnetization in large magneto-strictive materials like Ni and Co via the magnetoelastic coupling to excite spin waves. The attenuation of SAW, induced by spin wave excitation is known to be asymmetric in both the direction of propagation and a direction of an external magnetic field. Several studies attribute this asymmetry to the shear strain components in SAWs, which are asymmetric in the propagation direction. In particular, Tateno et al. observed that the asymmetry in attenuation becomes more pronounced by increasing the ratio of shear components to symmetric longitudinal components. However, to add a Si layer with several hundred nm in thick is required for achieving it, and the detailed mechanism for the asymmetry remains elusive. In this study, a composition gradient was introduced in a 20 nm thick magnetic layer, expecting that static strain from the gradient can enhance the asymmetry.