Magnetoresistance in a stripe-shaped two-dimensional electron gas

We measure large positive magnetoreistance in a nonplanar stripe-shaped two -dimensional electron gas (2DEG) in magnetic field up to 28 T. If the appli ed magnetic field is quasi-parallel to the substrate, the effective magneti c field becomes essentially nonuniform and sign alternating, because the or bital motion of 2DEG is sensitive to only the normal component of magnetic field. We find that the shape of the magnetoresistance traces is dramatical ly changed, when magnetic field becomes exactly parallel to the substrate p lane. We attribute such behaviour of the magnetoresistance to the formation of snake-like orbits which are channelling along the stripes. (C) 2001 Els evier Science B.V. All rights reserved.