Final Report on Investigation of the Electron Interactions in Graphene

Kim, Philip¹ 

[1] Columbia University

关键词: Graphene;    quantum transport;    electron Interactions;   

DOI  :  10.2172/1170221
RP-ID  :  DOE-COLUMBIA-FG02-05ER46215
PID  :  OSTI ID: 1170221

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

In graphene, combined with the real spin degree of freedom, which exhibits SU(2) symmetry, the total internal degrees of freedom of graphene carriers is thus described by a larger SU(4) symmetry, which produces a richer space for potential phenomena of emergent correlated electron phenomena. The major part of this proposal is exploring this unique multicomponent correlated system in the quantum limit. In the current period of DOE BES support we have made several key advances that will serve as a foundation for the new studies in this proposal. Employing the high-mobility encapsulated graphene heterostructures developed during the current phase of research, we have investigated spin and valley quantum Hall ferromagnetism in graphene and discovered a spin phase transition leading to a quantum spin Hall analogue. We have also observed the fractal quantum Hall effect arising from the Hofstadter???s butterfly energy spectrum. In addition, we have discovered multiband transport phenomena in bilayer graphene at high carrier densities.