  In this work, the edge physics of an Aharonov-Bohm interferometer (ABI)
defined on a two dimensional electron gas, subject to strong perpendicular
magnetic field B, is investigated. We solve the three dimensional Poisson
equation using numerical techniques starting from the crystal growth parameters
and surface image of the sample. The potential profiles of etched and gate
defined geometries are compared and it is found that the etching yields a
steeper landscape. The spatial distribution of the incompressible strips is
investigated as a function of the gate voltage and applied magnetic field,
where the imposed current is confined to. AB interference is investigated due
to scattering processes between two incompressible "edge-states".
