Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 26: Transport: Graphene - Electronic Properties and Transport 2 (jointly with DS, HL, MA, and TT)

O 26.8: Vortrag

Dienstag, 12. März 2013, 11:30–11:45, H17

Superlattice Effects on Electronic- and Transport Properties of Nanomaterials — •Fedor Tkatschenko, Viktor Krueckl, and Klaus Richter — Universität Regensbug, Germany

As recently discoverded by various groups [1,2] the electronic properties of two dimensional systems such as graphene show interesting characteristics in presence of superlattices including the emergence of extra Dirac points accompanied by an anisotropic velocity renormalization. Other interesting effects are Bloch-oscillations in presence of resonant Zener tunneling [3] giving rise to a negative differential conductance in the current voltage characteristics.

We focus on a scalar superlattice system extended by a constant mass term which opens a gap between the valance and conduction band in the minibandstructure. Analytical calculations within the effective Dirac model show that it is possible to tune the energy gap by variation of the superlattice amplitude. By additional numerical calculations based on the tight-binding model we confirm the analytical results.
[1] L. Brey and H. Fertig, Phys. Rev. Lett. 103, 046809 (2009)
M. Barbier, P. Vasilopoulos, and F. Peeters, Phys. Rev. B 81, 075438 (2010)
V. Krueckl and K. Richter, Phys. Rev. B 85, 115433 (2012)