Asymmetric scattering and diffraction of two-dimensional electrons at quantized tubes of magnetic flux

Abstract

The Hall conductivity of a high-mobility two-dimensional electron gas (2DEG) has been investigated in a distribution of quantized magnetic flux tubes (vortices) formed at a type-II superconducting ‘‘gate’’ layer. A pronounced suppression of the Hall effect was observed for long-Fermi wavelengths (as compared to the submicron vortex size) indicating a situation where electrons are diffracted by the flux quanta. In contrast, for shorter Fermi wavelengths the Hall conductivity has been found to be insensitive to the extreme inhomogeneity of the magnetic field and determined by the average field.