Nonequilibrium currents in the quantum Hall effect regime spatially resolved by transport experiment

Eddy currents in a constriction placed in a two-dimensional electron gas (2DEG) have been experimentally studied. The constrictions fabricated by the electron-beam lithography demonstrate quantum Hall effect in high magnetic field. Pronounced hysteresis of magnetoresistance is observed at Hall plateaus corresponding to integer filling factors v 1, 2 and 4 of a macroscopic 2DEG. The dependence of magnetoresistance hysteresis on the constriction width is obtained. The dependence contains the threshold value of width that points to the edge nature of eddy currents and enables us to determine the eddy currents area width, which is about 0.5 μm.