Tuning the strength of the IQHE at sharp edges: An experimental proposal based on Screening Theory

In this work, we exploit the findings of the screening theory of the integer quantized Hall effect based on the formation of the incompressible strips and their essential influence on the four point measurements. Certain experimental conditions are proposed to observe the transition of the quantized Hall effect from disorder dominated bulk regime to edge potential dominated edge regime within a phenomenological model, supported by model calculations. We suggest a Hall bar design on a cleaved edge overgrown wafer, which allows us to manipulate the edge potential profile from smooth to extremely sharp. For this particular sample design and by the help of a side-gate perpendicular to the two dimensional electron gas, it is shown that the plateau widths can be changed and even made to vanish when changing the edge potential profile and/or altering the current direction in the non-linear response regime. Such a control of the edge potential implies peculiar transport results when considering the screening theory, which includes direct Coulomb interaction explicitly. As a second investigation we also consider two different behaviors of the ohmic injection contacts, namely ideal and non-ideal, and show that if the injection contacts are non-ideal it is possible to measure directly the non-local transport taking place at the CEO samples. These experiments will shed light on the present understanding of the role of edge potential profile, under quantized Hall conditions.