Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 28: Transport properties

HL 28.2: Vortrag

Dienstag, 26. Februar 2008, 09:45–10:00, ER 164

Ballistic rectification in density-modulated 2D-systems — •Arkadius Ganczarczyk, Christian Notthoff, Bastian Marquardt, and Axel Lorke — Experimental Physics, Universität Duisburg-Essen and CeNIDE, Lotharstraße 1, 47057 Duisburg, Germany

We examine carriers in a 2-dimensional electron gas, which move ballistically along a boundary between two areas with different carrier densities. A voltage in the direction of the density-gradient (perpendicular to the applied current) is observed. The polarity of the transverse voltage depends on the direction of the density gradient and corresponds to a net current, which flows from the higher carrier density area to the lower density area. The direction of the transverse voltage is independent of the current polarity, which demonstrates rectification in the device. We also show that the transverse voltage depends on the relative variation of the carrier densities and the carrier mobility and has a parabolic dependence on the applied longitudinal bias. A theoretical model was developed for ballistic transport in density-modulated 2D-system, which includes the electric field needed to drive the applied current. This model is able to reproduce all major aspects of the experimental measurements. For small longitudinal currents experimental and simulated results agree well. However, the transverse voltage depends linearly on the longitudinal current whereas the experiment shows a parabolic dependence. This indicates that the presence of the transverse voltage cannot be fully described with a simple ballistic model.