期刊
PHYSICAL REVIEW B
卷 83, 期 20, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.83.205403
关键词
-
资金
- W. M. Keck Foundation
- Embassy of France
- NSF [DMR-0820382, DMR-1005880]
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [1005880] Funding Source: National Science Foundation
Graphene stacked in a Bernal configuration (60 degrees relative rotations between sheets) differs electronically from isolated graphene due to the broken symmetry introduced by interlayer bonds forming between only one of the two graphene unit cell atoms. A variety of experiments have shown that non-Bernal rotations restore this broken symmetry; consequently, these stacking varieties have been the subject of intensive theoretical interest. Most theories predict substantial changes in the band structure ranging from the development of a Van Hove singularity and an angle-dependent electron localization that causes the Fermi velocity to go to zero as the relative rotation angle between sheets goes to zero. In this work we show by direct measurement that non-Bernal rotations preserve the graphene symmetry with only a small perturbation due to weak effective interlayer coupling. We detect neither a Van Hove singularity nor any significant change in the Fermi velocity. These results suggest significant problems in our current theoretical understanding of the origins of the band structure of this material.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据