Chih-Huang Lai
Chih-Huang Lai
Chair Professor
National Tsing Hua University
Research Field: Materials for low energy consumption spintronics
Prof. Lai received his Ph.D. in Materials Science and Engineering from Stanford University in 1997. He joined Read-Rite Co. and worked on TMR and GMR heads. He became an assistant Professor in National Tsing Hua University (NTHU) in 1998. Prof. Lai was Dean of College of Engineering in NTHU (2016-2022) and is Associate Dean of College of Semiconductor Research. He is Tsing Hua Chair Professor and Micron Chair Professor. His research works focus on magnetic materials, spintronic devices and CIGS thin film solar cells. He has published more than 200 peer-reviewed SCI papers and obtained more than 50 patents. He is an IEEE Fellow and MRS-Taiwan Fellow.
A spin-orbit torque device toward energy-efficient neuromorphic Spintronics
Chih-Huang Lai a, Rudis Ismael Salinas a, Po-Chuan Chen a, Sheng-Huai Chen a, and Chao-Yao Yang b
a Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 300044, Taiwan.
b Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan.
The spintronic device has been considered as a promising candidate for neuromorphic computing because of its intrinsic non-volatility, ultrafast switching dynamics, and scalability. The spin-orbit torque (SOT) devices with precise control over the intermediate states for multi-levels have been demonstrated as promising artificial synapses for neuromorphic computing. In this study, we demonstrate a SOT device composed of Pd/Co/Ta trilayer features robust stabilization of intermediate magnetic states, which leads to precise controllability of multi-levels. Magnetization reversal of Pd/Co/Ta devices by SOT takes place through the gradual nucleation of reversed domains with restricted domain wall (DW) motion due to DW precession over Walker breakdown, which guarantees stable magnetic multi-levels. In addition, we also demonstrate that the switching of the SOT devices at the lowest energy consumption can occur at specific pulse duration, called chronaxie, commonly observed in biological neurons. Our findings will open a revolutionary avenue for establishing biomimetic neurons toward the energy and time efficient neuromorphic technology.