title: Magnetoplasmons in quasineutral epitaxial graphene nanoribbons.
abstract: We present an infrared transmission spectroscopy study of the inter-Landau-level excitations in quasineutral epitaxial graphene nanoribbon arrays. We observed a substantial deviation in energy of the L(0(-1)) → L(1(0)) transition from the characteristic square root magnetic-field dependence of two-dimensional graphene. This deviation arises from the formation of an upper-hybrid mode between the Landau-level transition and the plasmon resonance. In the quantum regime, the hybrid mode exhibits a distinct dispersion relation, markedly different from that expected for conventional two-dimensional systems and highly doped graphene.
authors.affiliation: National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Poumirol
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: W
authors.initials: W
authors.lastname: Yu
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA and CNRS/Institut Néel, BP166, 38042 Grenoble, France.
authors.forename: C
authors.initials: C
authors.lastname: Berger
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: W A
authors.initials: WA
authors.lastname: de Heer
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Smith
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: T
authors.initials: T
authors.lastname: Ohta
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: W
authors.initials: W
authors.lastname: Pan
authors.affiliation: Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris-Sud, F-91405 Orsay cedex, France.
authors.forename: M O
authors.initials: MO
authors.lastname: Goerbig
authors.affiliation: National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.
authors.forename: D
authors.initials: D
authors.lastname: Smirnov
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Jiang