Proximity Effect and Charging in Mesoscopic Normal Metal -   Superconductor Junction Systems
  Charging effects in mesoscopic junctions suppress the tunneling of electrons. In normal metal - superconductor systems they also suppress the proximity effect, thereby revealing the nature of the microscopic processes and of the ground state of the system. The effect can be made visible since the charging and proximity effect and hence the transport properties of the system can be modulated by gate voltages. If the superconducting electrode is isolated, electron number parity effect lead to an even-odd asymmetry in the proximity effect. 
C. Bruder, Rosario Fazio, and Gerd Sch\"on