We report on our theoretical investigation of the electron velocity in
(narrow) quantum-Hall systems, considering the out-of-linear-response regime.
The electrostatic properties of the electron system are obtained by the
Thomas-Fermi-Poisson nonlinear screening theory. The electron velocity
distribution as a function of the lateral coordinate is obtained from the slope
of the screened potential within the incompressible strips (ISs). The asymmetry
induced by the imposed current on the ISs is investigated, as a function of the
current intensity and impurity concentration. We find that the width of the IS
on one side of the sample increases linearly with the intensity of the applied
current and decreases with the impurity concentration.Comment: 6 pages, 2 figure
