  In this work, we investigate the spatial distributions and the widths of the
incompressible strips, i.e. the edgestates. The incompressible strips that
correspond to \nu=1,2 and 1/3 filling factors are examined in the presence of a
strong perpendicular magnetic field. We present a microscopic picture of the
fractional quantum Hall effect based interferometers, within a phenomenological
model. We adopt Laughlin quasi-particle properties in our calculation scheme.
In the fractional regime, the partially occupied lowest Landau level is assumed
to form an energy gap due to strong correlations. Essentially by including this
energy gap to our energy spectrum, we obtain the properties of the
incompressible strips at \nu=1/3. The interference conditions are investigated
as a function of the gate voltage and steepness of the confinement potential,
together with the strength of the applied magnetic field.
