Commensurability effects in two-dimensional electron gases with periodically arranged Ni and NiFe nanopillars

Abstract

We have investigated the magnetoresistance of high mobility two-dimensional electron gases (2DEG) under the influence of periodically arranged ferromagnetic nanopillars. A huge positive magnetoresistance and commensurability oscillations (COs) indicate that the 2DEG is subjected to a surprisingly strong modulation. Angular-dependent magnetoresistance measurements as well as the phase of the COs suggest that the modulation is dominated by electrostatic rather than by magnetic contributions.