Numerical studies of confined states in rotated bilayers of graphene
Numerical studies of confined states in rotated bilayers of graphene
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DOI：
10.1103/physrevb.86.125413
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发表时间：
2012-09-07
影响因子：
3.7
通讯作者：
Magaud, L.
中科院分区：
文献类型：
--
作者：
de Laissardiere, G. Trambly;Mayou, D.;Magaud, L.
旋转的石墨烯多层膜形成了一类新的石墨烯相关系统，其电子性质极大地依赖于旋转角度。研究表明，对于大旋转角度，双层的行为就像两个孤立的石墨烯平面。对于较小的角度，属于两层的狄拉克锥中的状态相互作用，导致出现两个货车霍韦奇性。随着旋转角的减小，态变得局域化，两个货车霍韦奇性在狄拉克能量处合并成一个峰。在这里，我们进一步考虑具有非常小的旋转角的双层。在这种情况下，明确定义的AA堆叠区域存在于双层超晶胞中，并且我们表明，对于[-gamma（t）+gamma（t）]范围内的能量，状态被限制在这些区域中，其中gamma（t）是面间平均相互作用。因此，局域态密度显示出与狄拉克能量不同的能量的离散峰。
Rotated graphene multilayers form a new class of graphene-related systems with electronic properties that drastically depend on the rotation angles. It has been shown that bilayers behave like two isolated graphene planes for large rotation angles. For smaller angles, states in the Dirac cones belonging to the two layers interact resulting in the appearance of two Van Hove singularities. States become localized as the rotation angle decreases and the two Van Hove singularities merge into one peak at the Dirac energy. Here we go further and consider bilayers with very small rotation angles. In this case, well-defined regions of AA stacking exist in the bilayer supercell and we show that states are confined in these regions for energies in the [-gamma(t) +gamma(t)] range with gamma(t) the interplane mean interaction. As a consequence, the local densities of states show discrete peaks for energies different from the Dirac energy.