Magnetoresistance of Electrons Channelled by Microscopic Magnetic Field Modulation

We report the magnetoresistance of two-dimensional electron gas, which is made of GaAs based epitaxial multilayers and laterally subjected to a periodic magnetic field. The modulation field is produced by an array of submicrometre ferromagnets fabricated at the surface of the heterostructure. The magnetoresistance of about 20% is found at low temperature 80K. The measurement is in quantitative agreement with semiclassical simulations, which reveal that the magnetoresistance is due to electrons trapped in snake orbits along lines of zero magnetic field.