Enhanced intervalley scattering of twisted bilayer graphene by periodic AB stacked atoms
Enhanced intervalley scattering of twisted bilayer graphene by periodic AB stacked atoms
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周期性AB堆叠原子增强扭曲双层石墨烯的层间散射
DOI：
10.1103/physrevb.85.235453
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发表时间：
2012-06-25
影响因子：
3.7
通讯作者：
He, Lin
中科院分区：
文献类型：
--
作者：
Meng, Lan;Chu, Zhao-Dong;He, Lin
采用输运测量和扫描隧道显微镜相结合的方法研究了SiC衬底上扭曲双层石墨烯的电子性质。我们报告的观察增强的谷间散射从一个狄拉克锥到其他，这有助于通过增加层间耦合强度弱本地化的扭曲双层石墨烯。我们的实验和分析表明，增强的谷间散射是密切相关的周期性AB堆叠原子（层1的A原子和层2的B原子具有相同的水平位置），打破了局部的石墨烯的亚晶格简并。我们进一步表明，这些周期性的AB堆叠原子影响谷间，但不intravalley散射。这一结果为原子级调控石墨烯的谷间散射提供了一种有效的方法。
The electronic properties of twisted bilayer graphene on SiC substrate were studied via a combination of transport measurements and scanning tunneling microscopy. We report the observation of enhanced intervalley scattering from one Dirac cone to the other, which contributes to weak localization of the twisted bilayer graphene by increasing the interlayer coupling strength. Our experiment and analysis demonstrate that the enhanced intervalley scattering is closely related to the periodic AB stacked atoms (the A atom of layer 1 and the B atom of layer 2 that have the same horizontal positions) that break the sublattice degeneracy of graphene locally. We further show that these periodic AB stacked atoms affect intervalley but not intravalley scattering. The result reported here provides an effective way to atomically manipulate the intervalley scattering of graphene.