Ultralow power spin-orbit torque magnetization switching induced by a non-epitaxial topological insulator on Si substrates
Ultralow power spin-orbit torque magnetization switching induced by a non-epitaxial topological insulator on Si substrates
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DOI：
10.1038/s41598-020-69027-6
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发表时间：
2020-07-22
影响因子：
4.6
通讯作者：
Hai, Pham Nam
中科院分区：
文献类型：
--
作者：
Khang, Nguyen Huynh Duy;Nakano, Soichiro;Hai, Pham Nam
拓扑绝缘体中的大自旋霍尔效应对超低功率自旋电子器件具有很大的吸引力。然而，TI的自旋霍尔角和自旋轨道扭矩（SOT）的评估通常在专用III-V族半导体衬底上生长的高质量单晶TI薄膜上进行。在这里，我们报告室温超低功率SOT磁化开关的亚铁磁层的非外延BiSb TI薄膜沉积在Si/SiO2衬底上。我们发现，非外延BiSb薄膜优于重金属和其他外延TI薄膜的有效自旋霍尔角和开关电流密度的一个到近两个数量级。室温下，BiSb的SOT临界开关电流密度低至7 × 10 ~（4）A/cm ~ 2。BiSb对晶体缺陷的鲁棒性表明了其在基于SOI的自旋电子器件中的潜在应用。
The large spin Hall effect in topological insulators (TIs) is very attractive for ultralow-power spintronic devices. However, evaluation of the spin Hall angle and spin-orbit torque (SOT) of TIs is usually performed on high-quality single-crystalline TI thin films grown on dedicated III-V semiconductor substrates. Here, we report on room-temperature ultralow power SOT magnetization switching of a ferrimagnetic layer by non-epitaxial BiSb TI thin films deposited on Si/SiO2 substrates. We show that non-epitaxial BiSb thin films outperform heavy metals and other epitaxial TI thin films in terms of the effective spin Hall angle and switching current density by one to nearly two orders of magnitude. The critical SOT switching current density in BiSb is as low as 7x10(4) A/cm(2) at room temperature. The robustness of BiSb against crystal defects demonstrate its potential applications to SOT-based spintronic devices.