MAGNETORESISTANCE IN DOT-LIKE AND ANTIDOTLIKE STRUCTURES

The magnetotransport in a two-dimensional electron gas in strongly modulated potentials is investigated. For dotlike and antidotlike lateral surface superlattices, a well-defined negative-differential-magnetoresistance behavior is observed followed by a large peak at low magnetic fields. Calculating the electron drift in the modulated potential by taking the external electric fields and the Hall field explicitly into account, two different groups of electrons are obtained, which are in a detailed balance. As only one of these groups contributes to the current flow, the occurrence of the negative differential magnetoresistance in two-dimensional lateral surface superlattices is thus explained. Moreover, the observed maximum in the magnetoresistance is also obtained from this model.