TWO-LEVEL RANDOM TELEGRAPH NOISE FROM MOVING VORTICES IN CLEAN <font>MgB</font>2 SINGLE CRYSTAL

The time evolution of the voltage response ( V ( t )) of the zero-field-cooled (ZFC) vortex matter for MgB 2 single crystals while applying a constant current application was recorded. Near the peak effect (PE) region, we observed a specific pattern of the V ( t ), that of a random telegraph signal for which the voltage mainly remained at two different levels. The origin of this random telegraph signal is closely related to the motional ordering of vortices resulting from the competition between the pinning and the Lorentz forces.