Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 47: Transport in high magnetic field/quantum-Hall-effect

HL 47.4: Vortrag

Donnerstag, 29. März 2007, 16:30–16:45, H14

The screening picture of the integer quantized Hall effect — •Afif Siddiki — Physics Dept., ASC, CeNS, LMU Munich, Germany

We implement the self-consistent Thomas-Fermi-Poisson approach to a homogeneous two dimensional electron system. First we summarize the findings of a recent model explaining the exact quantization of the Hall plateaus and the transition between them, within a local Ohm's law. Second we compute the electrostatic potential produced inside a semiconductor structure by a quantum point contact placed at the surface of the semiconductor and biased with appropriate voltages. The model is based on a semianalytical solution of the Laplace equation. Starting from the calculated confining potential, the self-consistent (screened) potential and the electron densities are calculated for finite temperature and magnetic field. We observe that there are mainly three characteristic rearrangements of the incompressible edge states which will determine the current distribution near a QPC.