Spin pumping and large field-like torque at room temperature in sputtered amorphous WTe$_{2-x}$ films

Fan Yihong; Li Hongshi; DC Mahendra; Peterson Thomas; Held Jacob; Sahu Protyush; Chen Junyang; Zhang Delin; Mkhoyan Andre Mkhoyan; Wang Jian-Ping

arXiv · 2002.09510

Spin pumping and large field-like torque at room temperature in sputtered amorphous WTe$_{2-x}$ films

Fan Yihong·Li Hongshi·DC Mahendra·Peterson Thomas·Held Jacob·Sahu Protyush·Chen Junyang·Zhang Delin·Mkhoyan Andre Mkhoyan·Wang Jian-Ping

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Abstract

We studied the spin-to-charge and charge-to-spin conversion at room temperature in sputtered WTe2-x (x=0.8)(t)/Co20Fe60B20(6 nm) heterostructures. Spin pumping measurements were used to characterize the spin-to-charge efficiency and the spin efficiency was calculated to be larger than ~0.035. Second harmonic Hall measurements were carried out to estimate the charge-to-spin conversion ratio. We found that the system exhibits a large field-like-torque (spin torque efficiency ~ 0.1) and small damping-like-torque (spin torque efficiency ~0.001) compared to that reported for heavy metals. High-resolution transmission electron microscopy images show that the WTe2-x layer is amorphous, which may enhance the spin swapping effect by inducing large interfacial spin orbit scattering, thus contributing to a large field like torque.

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Fan Yihong, Li Hongshi, DC Mahendra, Peterson Thomas, Held Jacob, Sahu Protyush, Chen Junyang, Zhang Delin, Mkhoyan Andre Mkhoyan, Wang Jian-Ping. 2020-02-21. Spin pumping and large field-like torque at room temperature in sputtered amorphous WTe$_{2-x}$ films. https://arxiv.org/abs/2002.09510

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