Dresden 2011 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 1: TR: Graphene 1 (jointly with MA, HL, and DY)

TT 1.5: Talk

Monday, March 14, 2011, 12:00–12:15, HSZ 03

Nanomachining a Tunneling Barrier in Graphene — •Patrick Barthold and Rolf J. Haug — Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover, Germany

Utilizing an atomic force microscope, graphene is nanomechanically structured. It is selectively folded in order to produce two dimensional systems that are only a few Angstrom apart. Aditionally, insulating lines are crafted within the sample without inducing any chemical contamination which, in contrast, is inevitable, when traditional structuring methods, e.g. etching procedures, are used. Such manufactured tunneling barriers are characterized by electrical transport measurements at low temperatures on an exemplary few-layer sample. In the conductivity through this barrier we find a gap around zero bias voltage. The conductivity shows a backgate dependent opening of a band gap in the sample. Due to the asymmetric design of the emitter and collector we find an asymmetry in the backgate dependent conductivity through the barrier.