ELECTRON-TRANSPORT IN THE TRANSITION REGIME BETWEEN 2D AND 0D BEHAVIOR

The influence of strongly modulating potentials on the magnetotransport properties of a two dimensional electron gas is investigated. On anti-dot like lateral surface superlattices, a well defined negative differential magnetoresistance occurs at low magnetic fields, which is followed by a large peak. In addition, an anomalous temperature behavior is observed. Calculating the electron drift in the modulated potential by taking the external electric fields and the Hall field explicitly into account, the occurrence of the negative differential magnetoresistance and the negative temperature coefficient is explained for the first time.