论文标题
各向异性超快旋转/山谷动力学
Anisotropic ultrafast spin/valley dynamics in WTe2 films
论文作者
论文摘要
WTE2 Weyl半学构成了自然破碎的反转对称性和强旋轨道耦合，这使得它对于在Picsecond时尺度内的异国情调旋转/山谷动力学有望。在这里，我们在室温下使用飞秒泵探针技术，以厘米尺度的单晶TD-WTE2膜推出各向异性超快自旋/山谷动力学。我们观察到整个自旋/山谷弛豫过程中的瞬态（〜0.8 ps） - valley内部过渡和随后的极化持续时间（〜5 ps）。此外，由于沿晶体方向的固有各向异性和外在基质元素效应，弛豫表现出了大约六倍和两倍对称性的各向异性。我们的结果为拓扑量子材料中的自旋/valleytronics的超快操纵提供了前景，用于无耗散的高速自旋/valleytronic设备。
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.
