Electrons in mesoscopically inhomogeneous magnetic fields
We investigated the low-field magnetoresistivity of a two-dimensional electron gas (2DEG) underneath microstructured ferromagnetic gratings. The strength and the direction of an externally applied magnetic field determines the strength and the shape of the micromagnet's stray field. Commensurability effects due to the imposed periodic magnetic field are in competition with similar effects resulting from a strain-induced periodic electrostatic potential, associated with the patterned ferromagnets on top of the heterojunction. The presence of both a periodic magnetic field and a periodic electrostatic potential gives rise to the interesting interference phenomena presented here.