title: Landau level spectroscopy of electron-electron interactions in graphene.
abstract: We present magneto-Raman scattering studies of electronic inter-Landau level excitations in quasineutral graphene samples with different strengths of Coulomb interaction. The band velocity associated with these excitations is found to depend on the dielectric environment, on the index of Landau level involved, and to vary as a function of the magnetic field. This contradicts the single-particle picture of noninteracting massless Dirac electrons but is accounted for by theory when the effect of electron-electron interaction is taken into account. Raman active, zero-momentum inter-Landau level excitations in graphene are sensitive to electron-electron interactions due to the nonapplicability of the Kohn theorem in this system, with a clearly nonparabolic dispersion relation.
authors: Laboratoire National des Champs Magnétiques Intenses, CNRS, (UJF, UPS, INSA), BP 166, 38042 Grenoble, Cedex 9, France.
authors: C
authors: C
authors: Faugeras
authors: Institut de Physique et Chimie des Matériaux de Strasbourg and NIE, UMR 7504, Université de Strasbourg and CNRS, BP43, 67034 Strasbourg, Cedex 2, France.
authors: S
authors: S
authors: Berciaud
authors: Laboratoire National des Champs Magnétiques Intenses, CNRS, (UJF, UPS, INSA), BP 166, 38042 Grenoble, Cedex 9, France.
authors: P
authors: P
authors: Leszczynski
authors: Laboratoire National des Champs Magnétiques Intenses, CNRS, (UJF, UPS, INSA), BP 166, 38042 Grenoble, Cedex 9, France.
authors: Y
authors: Y
authors: Henni
authors: Laboratoire National des Champs Magnétiques Intenses, CNRS, (UJF, UPS, INSA), BP 166, 38042 Grenoble, Cedex 9, France.
authors: K
authors: K
authors: Nogajewski
authors: Laboratoire National des Champs Magnétiques Intenses, CNRS, (UJF, UPS, INSA), BP 166, 38042 Grenoble, Cedex 9, France.
authors: M
authors: M
authors: Orlita
authors: National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors: T
authors: T
authors: Taniguchi
authors: National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors: K
authors: K
authors: Watanabe
authors: Department of Physics, Columbia University, New York, New York 10027, USA.
authors: C
authors: C
authors: Forsythe
authors: Department of Physics, Columbia University, New York, New York 10027, USA.
authors: P
authors: P
authors: Kim
authors: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom.
authors: R
authors: R
authors: Jalil
authors: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom.
authors: A K
authors: AK
authors: Geim
authors: Université Grenoble 1/CNRS, Laboratoire de Physique et de Modélisation des Milieux Condensés (UMR 5493), B.P. 166, 38042 Grenoble, Cedex 9, France.
authors: D M
authors: DM
authors: Basko
authors: Laboratoire National des Champs Magnétiques Intenses, CNRS, (UJF, UPS, INSA), BP 166, 38042 Grenoble, Cedex 9, France.
authors: M
authors: M
authors: Potemski