title: Energy-Dependent Chirality Effects in Quasifree-Standing Graphene.
abstract: We present direct experimental evidence of broken chirality in graphene by analyzing electron scattering processes at energies ranging from the linear (Dirac-like) to the strongly trigonally warped region. Furthermore, we are able to measure the energy of the van Hove singularity at the M point of the conduction band. Our data show a very good agreement with theoretical calculations for free-standing graphene. We identify a new intravalley scattering channel activated in case of a strongly trigonally warped constant energy contour, which is not suppressed by chirality. Finally, we compare our experimental findings with T-matrix simulations with and without the presence of a pseudomagnetic field and suggest that higher order electron hopping effects are a key factor in breaking the chirality near to the van Hove singularity.
authors.affiliation: Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.|II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Dombrowski
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany.
authors.forename: Wouter
authors.initials: W
authors.lastname: Jolie
authors.affiliation: Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia.
authors.forename: Marin
authors.initials: M
authors.lastname: Petrović
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Runte
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Craes
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Klinkhammer
authors.affiliation: Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička 46, 10000 Zagreb, Croatia.
authors.forename: Marko
authors.initials: M
authors.lastname: Kralj
authors.affiliation: Institut Ruđer Bošković, Bijenička 54, 10000 Zagreb, Croatia.
authors.forename: Predrag
authors.initials: P
authors.lastname: Lazić
authors.affiliation: Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Haim Levanon St 55, 6997801 Tel Aviv, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Sela
authors.affiliation: Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.|II. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Busse