Determination of the resistance across incompressible strips through imaging of charge motion

Using charge-accumulation imaging, we measure the charge flow across an incompressible strip and follow its evolution with magnetic field. The strip runs parallel to the edge of a gate deposited on the sample and forms atpositions where an exact number of integer Landau levels is filled. An RC model of charging fits the data well and enables us to determine the resistance across the strip. Surprisingly, we find that the strip becomes more resistive as its width decreases.