1. Anisotropic ultrafast spin/valley dynamics in WTe2 films
- Author
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Chen, Yequan, Chen, Zhendong, Chen, Yongda, Chen, Liming, Ning, Jiai, Liu, Bo, Zhang, Chunchen, Lu, Xianyang, Ruan, Xuezhong, Liu, Wenqing, Wang, Peng, Song, Fengqi, Zhang, Chunfeng, Wang, Fengqiu, Wu, Jing, He, Liang, Wang, Xuefeng, Zhang, Rong, and Xu, Yongbing
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences - Abstract
WTe2 Weyl semimetal hosts the natural broken inversion symmetry and strong spin orbit coupling, making it promising for exotic spin/valley dynamics within a picosecond timescale. Here, we unveil an anisotropic ultrafast spin/valley dynamics in centimeter-scale, single-crystalline Td-WTe2 films using a femtosecond pump-probe technique at room temperature. We observe a transient (~0.8 ps) intra-valley transition and a subsequent polarization duration (~5 ps) during the whole spin/valley relaxation process. Furthermore, the relaxation exhibits the remarkable anisotropy of approximately six-fold and two-fold symmetries due to the intrinsic anisotropy along the crystalline orientation and the extrinsic matrix element effect, respectively. Our results offer a prospect for the ultrafast manipulation of spin/valleytronics in topological quantum materials for dissipationless high-speed spin/valleytronic devices., Comment: 21 pages, 4 figures
- Published
- 2020
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