Observation of intervalley quantum interference in epitaxial monolayer tungsten diselenide.
Observation of intervalley quantum interference in epitaxial monolayer tungsten diselenide.
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外延单层二硒化钨层间量子干涉的观察
DOI：
10.1038/ncomms9180
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发表时间：
2015-09-01
影响因子：
16.6
通讯作者：
Xie M
中科院分区：
文献类型：
--
作者：
Liu H;Chen J;Yu H;Yang F;Jiao L;Liu GB;Ho W;Gao C;Jia J;Yao W;Xie M
单层过渡金属双硫族化物的特殊电子结构，如自旋谷耦合带边，引起了人们对基于这些二维材料的潜在自旋电子学和谷电子学应用的极大兴趣。在这项工作中，我们报告的准粒子干涉图案在单层WSe 2使用低温扫描隧道光谱的实验观察。我们观察到谷间量子干涉涉及的导带中的Q谷由于自旋守恒散射过程，而自旋翻转谷间散射是不存在的。我们的结果明确地建立自旋谷耦合的存在，并确认大自旋分裂在Q谷。重要的是，低效的自旋翻转散射意味着单层WSe 2中的长谷和自旋寿命，这是谷自旋电子学应用的关键品质因数。 过渡金属二硫属化物的单层具有自旋电子学和谷电子学中应用所需的许多性质。在这里，作者实验观察谷间量子干涉涉及导带Q谷二硒化钨。
The extraordinary electronic structures of monolayer transition metal dichalcogenides, such as the spin–valley-coupled band edges, have sparked great interest for potential spintronic and valleytronic applications based on these two-dimensional materials. In this work, we report the experimental observation of quasi-particle interference patterns in monolayer WSe2 using low-temperature scanning tunnelling spectroscopy. We observe intervalley quantum interference involving the Q valleys in the conduction band due to spin-conserving scattering processes, while spin-flipping intervalley scattering is absent. Our results establish unequivocally the presence of spin–valley coupling and affirm the large spin splitting at the Q valleys. Importantly, the inefficient spin-flipping scattering implies long valley and spin lifetime in monolayer WSe2, which is a key figure of merit for valley-spintronic applications. Monolayers of transition metal dichalcogenides have many of the properties required for applications in spintronics and valleytronics. Here, the authors experimentally observe intervalley quantum interference involving conduction band Q-valleys in tungsten diselenide.