Description

2011/06/24, Klaus Richter  (Univ. of Regensburg)
Place:  Sala de Seminarios del Departamento de Física Teórica e Historia de la Ciencia
Time: 12h
Title: Edge Phenomena in Graphene

Abstract
As distinct from the (smooth) confinement potential of semiconductor-based
lateral quantum dots, boundaries in graphene nanostructures, arising from
abrupt lattice termination, are (locally) composed of zigzag- or armchair-type
atomic arrangements. They for instance characterize nanoribbons, can give rise
to peculiar "edge states"  and usually vary along the edges of a graphene
quantum dot. Thereby the edges affect crucially the spectral and transport
properties of graphene nanostructures.

Here I develop a theoretical approach that is capable of handling such effects
in graphene quantum dots. I will first derive an exact expression for the
Green function of a mesoscopic graphene flake and then employ a semiclassical
path integral approach.
This allows for understanding peculiar phase-coherence effects in graphene
in terms of interference arising from the graphene pseudospin dynamics.