Josephson Current in Superconductor/Two-Dimensional-Electron-Gas Junctions

Abstract

During the discussion of the subharmonic gap structures, the phase of the superconducting electrodes was neglected. We shall see in this chapter that phase coherence is crucial for the occurrence of a Josephson supercurrent. In the first part of this chapter, the theoretical concepts will be discussed, starting with the simplest model of an ideal one-dimensional junction, without any barriers at the SN interface and with no Fermi velocity mismatch. Later on, more elaborate models will be introduced, which describe the experimental situation more appropriately.