  An asymmetric break-down of the integer quantized Hall effect is
investigated. This rectification effect is observed as a function of the
current value and its direction in conjunction with an asymmetric lateral
confinement potential defining the Hall-bar. Our electrostatic definition of
the Hall-bar via Schottky-gates allows a systematic control of the steepness of
the confinement potential at the edges of the Hall-bar. A softer edge (flatter
confinement potential) results in more stable Hall-plateaus, i.e. a break-down
at a larger current density. For one soft and one hard edge the break-down
current depends on the current direction, resembling rectification. This
non-linear magneto-transport effect confirms the predictions of an emerging
screening theory of the IQHE.
