Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 9: Poster 1

HL 9.2: Poster

Montag, 23. März 2009, 14:30–17:00, P2

Temperature dependence of the conductivity of ballistic graphene — •Matthias Bräuninger¹, Markus Müller², and Björn Trauzettel¹ — ¹Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany — ²Department of Theoretical Physics, University of Geneva, CH-1211 Geneva, Switzerland

We investigate the temperature dependence of the conductivity in ballistic graphene using Landauer transport theory. The finite temperature only enters in the Fermi distribution functions of the reservoirs, but not in any inelastic scattering strength. Remarkably, we obtain results that are qualitatively in agreement with many features that were recently observed in transport measurements on (high mobility) suspended graphene. The conductivity at high temperature T and low density n grows linearly with T, while at low T and high n it follows σ∼ √|n|. In the intermediate regime the conductivity is a non-monotonic function of either T or n, exhibiting a minimum at T=0.693 ℏ v√|n| where v is the Fermi velocity.