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 applied magnetic field is quasi-parallel to the substrate, the effective magnetic field becomes essentially nonuniform and sign alternating, because the orbital motion of 2DEG is sensitive to only the normal component of magnetic field. We find that the shape of the magnetoresistance traces is dramatically changed, when magnetic field becomes exactly parallel to the substrate plane. We attribute such behaviour of the magnetoresistance to the formation of snake-like orbits which are channelling along the stripes. (C) 2001 Elsevier Science B.V. All rights reserved.