  Andreev-reflection dominated transport is demonstrated in Al/n-In0.38Ga0.62As
superconductor-semiconductor junctions grown by molecular beam epitaxy on
GaAs(001). High junction transparency was achieved in low-doped devices by
exploiting Si interface bilayers to suppress the native Schottky barrier. It is
argued that this technique is ideally suited for the fabrication of ballistic
transport hybrid microstructures.
