Topological defects in the edge-state structure in a bilayer electron system

Abstract

We experimentally demonstrate formation of pointlike topological defects in the edge-state structure in the quantum Hall effect regime. By using of a selective population technique, we investigate equilibration processes between the edge states in bilayer electron structures with a high tunneling rate between layers. Unexpected flattening of the I-V curves in a perpendicular magnetic field at a specific filling factor combination and the recovery of the conventional nonlinear I-V characteristics in tilted fields give a strong evidence for the existence of topological defects.