Andreev reflection at superconductor-semiconductor interfaces in high magnetic fields

A special type of magnetic edge states is formed at the interface between a normal material and a superconductor. As the peculiar character of confine ment due to a superconducting pair potential gives rise to Andreev reflecti on of electron-like excitations from the normal region into hole-like ones, these edge states can be viewed, in a semiclassical picture, as alternatin g skipping orbits of electrons and holes. We provide a fully quantum-mechan ical description of these Andreev edge states, taking into account non-idea lities of the interface such as Fermi-velocity mismatch and interface scatt ering as well as screening currents in the superconductor. (C) 2001 Elsevie r Science B.V. All rights reserved.