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F. Libisch, J. Güttinger, S. Rotter, C Stampfer, T. Ihn, K. Ensslin, J. Burgdörfer:
"Simulation of the development of Landau Levels in Graphene Quantum Dots";
Poster: Graphene week 2010, Maryland, USA; 2010-04-19 - 2010-04-23.

We investigate the electronic eigenstates of graphene quantum dots with realistic size (~60 nm
diameter) in the presence of a perpendicular magnetic field B. Numerical tight-binding
calculations and Coulomb-blockade measurements performed near the Dirac point show the
evolution from the linear density of states at B=0 to the Landau level regime as a function of
magnetic field. For low fields, localization effects at the edges strongly influence eigenstates [see
Fig. 1(a)], while for high fields the energy spectrum becomes independent of the confinement
geometry [see Fig. 1(b)] and closely follows predictions based on the Dirac equation for
massless fermions. We show how this parametric dependence of eigenenergies can be exploited
to pin down the electron-hole crossover region in graphene quantum dots.

Graphene, Landau Levels, Quantum dots

http://publik.tuwien.ac.at/files/PubDat_186249.pdf