  A hybrid superconductor--two-dimensional electron gas microdevice is
presented. Its working principle is based on the suppression of Andreev
reflection at the superconductor-semiconductor interface caused by a magnetic
barrier generated by a ferromagnetic strip placed on top of the structure.
Device switching is predicted with fields up to some mT and working frequencies
of several GHz, making it promising for applications ranging from microswitches
and storage cells to magnetic field discriminators.
