title: Raman spectroscopy study of rotated double-layer graphene: misorientation-angle dependence of electronic structure.
abstract: We present a systematic Raman study of unconventionally stacked double-layer graphene, and find that the spectrum strongly depends on the relative rotation angle between layers. Rotation-dependent trends in the position, width and intensity of graphene 2D and G peaks are experimentally established and accounted for theoretically. Our theoretical analysis reveals that changes in electronic band structure due to the interlayer interaction, such as rotational-angle dependent Van Hove singularities, are responsible for the observed spectral features. Our combined experimental and theoretical study provides a deeper understanding of the electronic band structure of rotated double-layer graphene, and leads to a practical way to identify and analyze rotation angles of misoriented double-layer graphene.
authors.affiliation: Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: Kwanpyo
authors.initials: K
authors.lastname: Kim
authors.forename: Sinisa
authors.initials: S
authors.lastname: Coh
authors.forename: Liang Z
authors.initials: LZ
authors.lastname: Tan
authors.forename: William
authors.initials: W
authors.lastname: Regan
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Yuk
authors.forename: Eric
authors.initials: E
authors.lastname: Chatterjee
authors.forename: M F
authors.initials: MF
authors.lastname: Crommie
authors.forename: Marvin L
authors.initials: ML
authors.lastname: Cohen
authors.forename: Steven G
authors.initials: SG
authors.lastname: Louie
authors.forename: A
authors.initials: A
authors.lastname: Zettl