Spin-orbit Torque Switching in an All-Van der Waals Heterostructure

• Main Authors: Shin, Inseob, Cho, Won Joon, An, Eun-Su, Park, Sungyu, Jeong, Hyeon-Woo, Jang, Seong, Baek, Woon Joong, Park, Seong Yong, Yang, Dong-Hwan, Seo, Jun Ho, Kim, Gi-Yeop, Ali, Mazhar N, Choi, Si-Young, Lee, Hyun-Woo, Kim, Jun Sung, Kim, Sungdug, Lee, Gil-Ho
• Format: Journal Article
• Language: English
• Published: 18.02.2021
• Subjects: Physics - Materials Science; Physics - Mesoscale and Nanoscale Physics
• DOI: 10.48550/arxiv.2102.09300

Current-induced control of magnetization in ferromagnets using spin-orbit torque (SOT) has drawn attention as a new mechanism for fast and energy efficient magnetic memory devices. Energy-efficient spintronic devices require a spin-current source with a large SOT efficiency (${\xi}$) and electrical conductivity (${\sigma}$), and an efficient spin injection across a transparent interface. Herein, we use single crystals of the van der Waals (vdW) topological semimetal WTe$_2$ and vdW ferromagnet Fe$_3$GeTe$_2$ to satisfy the requirements in their all-vdW-heterostructure with an atomically sharp interface. The results exhibit values of ${\xi}{\approx}4.6$ and ${\sigma}{\approx}2.25{\times}10^5 {\Omega}^{-1} m^{-1}$ for WTe$_2$. Moreover, we obtain the significantly reduced switching current density of $3.90{\times}10^6 A/cm^2$ at 150 K, which is an order of magnitude smaller than those of conventional heavy-metal/ ferromagnet thin films. These findings highlight that engineering vdW-type topological materials and magnets offers a promising route to energy-efficient magnetization control in SOT-based spintronics.