Interaction-mediated asymmetries of the quantized Hall effect

¹  Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilans-Universität - Theresienstrasse 37, 80333 Munich, Germany, EU
²  Physics Department, Faculty of Arts and Sciences, Mugla University - 48170-Kötekli, Mugla, Turkey
³  Institut für Experimentelle und Angewandte Physik, Universität Regensburg - D-93040 Regensburg, Germany, EU

Corresponding author: siddiki@mu.edu.tr

Received: 30 July 2009
Accepted: 22 September 2009

Abstract

Experimental and theoretical investigations on the integer quantized Hall effect in gate-defined narrow Hall bars are presented. At low electron mobility the classical (high-temperature) Hall resistance line cuts through the center of all Hall plateaus. In contrast, for our high-mobility samples the intersection point, at even filling factors ν = 2, 4, ..., is clearly shifted towards larger magnetic fields B. This asymmetry is in good agreement with predictions of the screening theory, i.e. taking Coulomb interaction into account. The observed effect is directly related to the formation of incompressible strips in the Hall bar. The spin-split plateau at ν = 1 is found to be almost symmetric regardless of the mobility. We explain this within the so-called effective g-model.