Andreev reflection in Si-engineered Al/InGaAs hybrid junctions

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.