Quantum Hall effect in a high-mobility two-dimensional electron gas on the surface of a cylinder
Özet
The quantum Hall effect is investigated in a high-mobility two-dimensional electron gas on the surface of a cylinder. This special topology leads to a spatially varying filling factor along the current path. The resulting inhomogeneous current-density distribution gives rise to additional features in the magnetotransport, such as resistance asymmetry and modified longitudinal resistances. We experimentally demonstrate that the asymmetry relations satisfied in the integer filling factor regime are valid also in the transition regime to noninteger filling factors, thereby suggesting a more general form of these asymmetry relations. A model is developed based on the screening theory of the integer quantum Hall effect that allows the self-consistent calculation of the local electron density and thereby the local current density including the current along incompressible stripes. The model, which also includes the so-called "static skin effect" to account for the current-density distribution in the compressible regions can explain the main experimental observations. Due to the existence of an incompressible-compressible transition in the bulk, the system behaves always metal-like in contrast to the conventional Landauer-Buttiker description, in which the bulk remains completely insulating throughout the quantized Hall plateau regime.
