Observation of the out-of-plane polarized spin current from CVD grown WTe2

Shuyuan Shi; Jie Li; Chuang-Han Hsu; Kyusup Lee; Yi Wang; Li Yang; Junyong Wang; Qisheng Wang; Hao Wu; Wenfeng Zhang; Goki Eda; Gengchiau Liang; Haixin Chang; Hyunsoo Yang

arXiv · 2106.04154

Observation of the out-of-plane polarized spin current from CVD grown WTe2

Shuyuan Shi·Jie Li·Chuang-Han Hsu·Kyusup Lee·Yi Wang·Li Yang·Junyong Wang·Qisheng Wang·Hao Wu·Wenfeng Zhang·Goki Eda·Gengchiau Liang·Haixin Chang·Hyunsoo Yang

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Abstract

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.

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Shuyuan Shi, Jie Li, Chuang-Han Hsu, Kyusup Lee, Yi Wang, Li Yang, Junyong Wang, Qisheng Wang, Hao Wu, Wenfeng Zhang, Goki Eda, Gengchiau Liang, Haixin Chang, Hyunsoo Yang. 2021-06-08. Observation of the out-of-plane polarized spin current from CVD grown WTe2. https://arxiv.org/abs/2106.04154

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