Magnetization switching using damping-like spin orbit torque from sputtered Weyl semimetal WTe2
Presenter: Xiang (Shaun) Li from Stanford Shan X. Wang group
Abstract: New materials that can efficiently generate spin-orbit toques are highly desired for low power and high-speed spin-orbit torque MRAM (SOT-MRAM) used in cache applications. However, the Bi-based topological insulators showing high SOT efficiency degrade the total readout on/off ratio due to their high resistivity as electrodes. We will explore conductive topological materials such as Weyl semimetals as efficient spin-orbit-torque generator using industrial applicable sputtering techniques.
We successfully deposited WTe2 thin film using ion-beam sputtering techniques exhibiting signature Raman peaks. We found a sizable charge-to-spin conversion efficiency of 0.4 in WTe2/CoFeB-based structures using two different techniques. Using the damping-like torque found in WTe2, an in-plane magnetized CoFeB layer is switched electrically under a current density of 1-2MA/cm2. This work demonstrates that sputtered conductive WTe2 thin films possess a switching power efficiency comparable with or better than the best heavy metal materials.
Related to Task 2776.056. Exploring new topological materials and interfaces for advanced SOT-MRAM
Please note: This meeting is only available to the JUMP research community, such as Principal Investigators, Postdoc researchers, Students, and Industry/Government liaisons