We report excess longitudinal resistivity of a high-mobility two-dimensional electron gas (2DEG) in a random distribution of submicrometer magnetic-flux tubes (vortices) which are formed at the 2DEG by a superconducting gate layer. The results are explained in terms of small-angle scattering of ballistic electrons by the magnetic-field inhomogeneities.

• Received 29 November 1993

DOI:https://doi.org/10.1103/PhysRevB.49.5749