Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, Greifswald, Germany.
Phys Rev Lett. 2012 Feb 10;108(6):066402. doi: 10.1103/PhysRevLett.108.066402. Epub 2012 Feb 9.
The experimentally observed metal-to-insulator transition in hydrogenated graphene is numerically confirmed for actual sized graphene samples and realistic impurity concentrations. The eigenstates of our tight-binding model with substitutional disorder corroborate the formation of electron-hole puddles with characteristic length scales comparable to the ones found in experiments. The puddles cause charge inhomogeneities and tend to suppress Anderson localization. Even though, monitoring the charge carrier quantum dynamics and performing a finite-size scaling of the local density of states distribution, we find strong evidence for the existence of localized states in graphene nanoribbons with short-range but also correlated long-range disorder.
实验观测到的氢化石墨烯中的金属-绝缘体转变在实际尺寸的石墨烯样品和实际杂质浓度下得到了数值证实。我们的具有替代无序的紧束缚模型的本征态证实了形成电子-空穴水坑的过程，其特征长度尺度与实验中发现的长度尺度相当。这些水坑导致电荷不均匀，并倾向于抑制安德森局域化。尽管如此，通过监测电荷载流子量子动力学并对局域态密度分布进行有限尺寸标度，我们发现了在具有短程但也具有相关长程无序的石墨烯纳米带中存在局域态的有力证据。
