Confinement-potential tuning: From nonlocal to local transport

Abstract
We investigate experimentally the influence of the boundary confining potential on edge channel transport in the quantum Hall regime. It is demonstrated that the steepness of the confining potential and therefore the edge channel separation is much more relevant for transport phenomena observed than ‘‘bulk’’ properties such as the electron mean free path. We change the edge potential by brief illumination using a light-emitting diode and study the crossover from nonlocal to local transport.