Quantum Properties of an Andreev Phase Gradiometer
  A new class of nano-structure devices is suggested, based on interference from the order parameter phase gradient of a single superconductor (S) in contact with a single normal metallic lead (N). By solving the Bogoliubov - de Gennes equation in two dimensions, it is demonstrated that the electrical conductance of a normal conductor of width $M$ in contact with a superconductor will oscillate as the phase gradient $v$ at 90$^0$ to the interface is increased. This effect is enhanced by the presence of a Schottky barrier at the interface and is also present in $N-S-N$ structures. 
P Cook, V C Hui and C J Lambert