Inverted hysteresis of magnetoresistance of a 2DEG at integer filling factors

We report on an observation of giant hysteresis of longitudinal magnetoresistance of a constriction placed in a macroscopic two‐dimensional electron gas at integer filling factors. The most striking feature of observed phenomenon is the inverted form of hysteresis loops which is manifested in advanced system response to a small change of external magnetic field. We found that the resistance in the region of hysteresis loop relaxes in a stepwise manner, that is phenomenologically similar to Barkhausen jumps.