title: Atomic and electronic structure of trilayer graphene/SiC(0001): Evidence of Strong Dependence on Stacking Sequence and charge transfer.
abstract: The transport properties of few-layer graphene are the directly result of a peculiar band structure near the Dirac point. Here, for epitaxial graphene grown on SiC, we determine the effect of charge transfer from the SiC substrate on the local density of states (LDOS) of trilayer graphene using scaning tunneling microscopy/spectroscopy and angle resolved photoemission spectroscopy (ARPES). Different spectra are observed and are attributed to the existence of two stable polytypes of trilayer: Bernal (ABA) and rhomboedreal (ABC) staking. Their electronic properties strongly depend on the charge transfer from the substrate. We show that the LDOS of ABC stacking shows an additional peak located above the Dirac point in comparison with the LDOS of ABA stacking. The observed LDOS features, reflecting the underlying symmetry of the two polytypes, were reproduced by explicit calculations within density functional theory (DFT) including the charge transfer from the substrate. These findings demonstrate the pronounced effect of stacking order and charge transfer on the electronic structure of trilayer or few layer graphene. Our approach represents a significant step toward understand the electronic properties of graphene layer under electrical field.
authors.affiliation: Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France.
authors.forename: Debora
authors.initials: D
authors.lastname: Pierucci
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, UMR CNRS 7590, Sorbonne Universités, UPMC, Univ. Paris VI, MNHN, IRD, 4 Place Jussieu, 75005 Paris, France.|Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Brumme
authors.affiliation: Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Girard
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, UMR CNRS 7590, Sorbonne Universités, UPMC, Univ. Paris VI, MNHN, IRD, 4 Place Jussieu, 75005 Paris, France.
authors.forename: Matteo
authors.initials: M
authors.lastname: Calandra
authors.affiliation: Synchrotron-SOLEIL, Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France.
authors.forename: Mathieu G
authors.initials: MG
authors.lastname: Silly
authors.affiliation: Synchrotron-SOLEIL, Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France.
authors.forename: Fausto
authors.initials: F
authors.lastname: Sirotti
authors.affiliation: Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC, CEA-CNRS UMR 3680, CEA-Saclay, F-91191 Gif-sur-Yvette, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Barbier
authors.affiliation: Departimento di Fisica, Università di Roma La Sapienza, Piazzale Aldo Moro 5, I-00185 Roma, Italy.|Graphene Labs, Fondazione Istituto Italiano di Tecnologia, Via Morego, I-16163 Genova, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mauri
authors.affiliation: Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N-Marcoussis, 91460 Marcoussis, France.
authors.forename: Abdelkarim
authors.initials: A
authors.lastname: Ouerghi