Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

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

HL 47.5: Vortrag

Donnerstag, 29. März 2007, 16:45–17:00, H14

Edge versus bulk current in the quantum Hall effect regime — •Josef Oswald — Institute of Physics, University of Leoben, Franz Josef Str. 18, A-8700 Leoben, Austria

The question about the role of edge and bulk current for the integer quantum Hall effect (IQHE) is still a major topic of the ongoing discussions. The importance of this question is highlighted by experimental results obtained by probing the lateral potential distribution in the IQHE-regime[1]. In order to compare this experimental results with theory, a transport model is needed, which is able to capture sample properties close to the real experimental conditions like e.g. sample geometry and non-ideal contacts. In recent papers [2,3,4] we have demonstrated, that on the basis of a network model it is possible to account for complex sample geometries and we have further shown, that our network model is able to treat edge and bulk currents on an equal footing. This gives us the ability to address the lateral current distribution in QHE samples. For the pure plateau regime we get a homogeneous distribution of the current in the bulk region, while for the transition regime between plateaus we get an enhancement of the current density near the edges.

[1] E. Ahlswede et al., Physica E12, 165 (2002)

[2] J.Oswald et al., Phys. Rev. B74(15), 153315 (2006)

[3] M.Oswald et al., Phys.Rev. B72(3), 035334 (2005)

[4] J.Oswald et al., J. Phys.: Condens. Matter 18, R101-R138 (2006)