Magnetic-field-induced instabilities in localized two-dimensional electron systems

We report density dependent instabilities in the localized regime of mesoscopic two-dimensional electron systems (2DESs) with intermediate strength of background disorder. They are manifested by strong resistance oscillations induced by high perpendicular magnetic fields B-perpendicular to. While the amplitude of the oscillations is strongly enhanced with increasing B-perpendicular to, their position in density remains unaffected. The observation is accompanied by an unusual behavior of the temperature dependence of resistance and activation energies. We suggest the interplay between a strongly interacting electron phase and the background disorder as a possible explanation.