Berlin 2015 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 12: Graphene: mostly Theory (with O/TT)
HL 12.10: Vortrag
Montag, 16. März 2015, 17:15–17:30, ER 164
Local sublattice symmetry breaking in graphene with centro-symmetric deformations — Martin Schneider1, Daiara Faria2, •Silvia Viola Kusminskiy1, and Nancy Sandler3 — 1Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universitaet Berlin, Deutschland — 2Universidade Federal Fluminense, Rio de Janeiro, Brasil — 3Ohio University, Ohio, United States
A generic deformation of a graphene sheet causes inhomogeneous strain which results in an effective, non-uniform pseudomagnetic field acting on the Dirac fermions. This can provide an alternative route to confine and control charge carriers in graphene. We investigate the electronic properties of a graphene sheet in the presence of an out-of-plane deformation with centro-symmetric geometry, for which the pseudo-magnetic field presents trigonal symmetry. We address the question of confinement of electrons due to this deformation, using a scattering formalism based on the continuum description of graphene. In particular we study the local density of states (LDOS) of the electronic carriers, and show that this type of deformation causes a noticeable imbalance in the distribution of charge density between the two graphene inequivalent sublattices even for small deformations. We perform exact numerical calculations and show that the results are well described within an analytical, perturbative approach for small deformations. We discuss our results in view of recent experimental findings.