Experimental investigation of the edge states structure at fractional   filling factors
  We experimentally study electron transport between edge states in the fractional quantum Hall effect regime. We find an anomalous increase of the transport across the 2/3 incompressible fractional stripe in comparison with theoretical predictions for the smooth edge potential profile. We interpret our results as a first experimental demonstration of the intrinsic structure of the incompressible stripes arising at the sample edge in the fractional quantum Hall effect regime. 
E.V. Deviatov, V.T. Dolgopolov, A. Lorke, W. Wegscheider, A.D. Wieck