Weyl semimetal Td-phase WTe2 possesses the spin-resolved band structure with strong spin-orbit coupling, holding promises as a useful spin source material. The noncentrosymmetric crystalline structure of Td-WTe2 endows the generation of the out-of-plane polarized spin, which is of great interest in magnetic memory applications. Previously, WTe2 was explored in spin devices based on mechanically exfoliated single crystal flakes with a size of micrometers. For practical spintronics applications, it is highly desirable to implement wafer-scale thin films. In this work, we utilize centimeter-scale chemical vapor deposition (CVD)-grown Td-WTe2 thin films and study the spin current generation by the spin torque ferromagnetic resonance technique. We find the in-plane and out-of-plane spin conductivities of 7.36 x 10^3 (h/2e) (ohm-m)^-1 and 1.76 x 10^3 (h/2e) (ohm-m)^-1, respectively, in CVD-growth 5 nm-WTe2. We further demonstrate the current-induced magnetization switching in WTe2/NiFe at room temperature in the domain wall motion regime, which may invigorate potential spintronic device innovations based on Weyl semimetals.
@article{arxiv.2106.04154,
title = {Observation of the out-of-plane polarized spin current from CVD grown WTe2},
author = {Shuyuan Shi and Jie Li and Chuang-Han Hsu and Kyusup Lee and Yi Wang and Li Yang and Junyong Wang and Qisheng Wang and Hao Wu and Wenfeng Zhang and Goki Eda and Gengchiau Liang and Haixin Chang and Hyunsoo Yang},
journal= {arXiv preprint arXiv:2106.04154},
year = {2021}
}