Horaguchi Taisuke, He Cong, Wen Zhenchao, Nakayama Hayato, Ohkubo Tadakatsu, Mitani Seiji, Sukegawa Hiroaki, Fujimoto Junji, Yamanoi Kazuto, Matsuo Mamoru, Nozaki Yukio
Department of Physics, Keio University, Yokohama 223-8522, Japan.
Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Ibaraki, Japan.
Sci Adv. 2025 May 9;11(19):eadr9481. doi: 10.1126/sciadv.adr9481.
Green materials for efficient charge-to-spin conversion are desired for common spintronic applications. Recent studies have documented the efficient generation of spin torque using spin-orbit interactions (SOIs); however, SOI use relies on the employment of rare metals such as platinum. Here, we demonstrate that a nanometer-thick gradient from silicon to aluminum, which consists of readily available elements from earth resources, can produce a spin torque as large as that of platinum despite the weak SOI of these compositions. The spin torque efficiency can be improved by decreasing the thickness of the gradient, while a sharp interface was not found to increase the spin torque. Moreover, the electric conductivity of the gradient material can be up to twice as large as that of platinum, which provides a way to reduce Joule heating losses in spintronic devices.
对于常见的自旋电子学应用而言，需要用于高效电荷到自旋转换的绿色材料。最近的研究记录了利用自旋轨道相互作用（SOI）高效产生自旋扭矩；然而，SOI的使用依赖于诸如铂等稀有金属。在此，我们证明了从硅到铝的纳米厚梯度结构，其由地球上容易获取的元素组成，尽管这些成分的SOI较弱，但仍能产生与铂一样大的自旋扭矩。通过减小梯度结构的厚度可以提高自旋扭矩效率，而未发现尖锐界面会增加自旋扭矩。此外，梯度材料的电导率可高达铂的两倍，这为减少自旋电子器件中的焦耳热损耗提供了一种方法。
