High-Energy Limit of Massless Dirac Fermions in Multilayer Graphene using Magneto-Optical Transmission Spectroscopy

Paulina Plochocka (1) , Clément Faugeras (1) , Milan Orlita (1) , Marcin L. Sadowski (1) , Gérard Martinez (1) , Marek Potemski (1) , Mark O. Goerbig (2) , Jean-Noël Fuchs (2) , Claire Berger (3) , Walter A. de Heer (4)

1 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble
2 LPS - Laboratoire de Physique des Solides
3 NEEL - QuantECA - Circuits électroniques quantiques Alpes
4 Georgia Institute of Technology [Atlanta]

We have investigated the absorption spectrum of multilayer graphene in high magnetic fields. The low energy part of the spectrum of electrons in graphene is well described by the relativistic Dirac equation with a linear dispersion relation. However, at higher energies (>500 meV) a deviation from the ideal behavior of Dirac particles is observed. At an energy of 1.25 eV, the deviation from linearity is 40 meV. This result is in good agreement with the theoretical model, which includes trigonal warping of the Fermi surface and higher-order band corrections. Polarization-resolved measurements show no observable electron-hole asymmetry.

Domaines: Autre [cond-mat.other]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Paulina Plochocka, Clément Faugeras, Milan Orlita, Marcin L. Sadowski, Gérard Martinez, et al.. High-Energy Limit of Massless Dirac Fermions in Multilayer Graphene using Magneto-Optical Transmission Spectroscopy. Physical Review Letters, 2008, 100 (8), pp.087401. ⟨10.1103/PhysRevLett.100.087401⟩. ⟨hal-00413949⟩