Nanowires and nanofilms: Superconductivity in quantum-size regime

Quantum confinement is the major mechanism governing superconductivity in highly crystalline metallic specimens with nanoscale dimensions. Changes in the single-electron spectrum due to size quantization result in quantum-size variations of the superconducting properties (e.g., critical temperature and critical magnetic field) with profound enhancements at the points of the superconducting resonances. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations for clean metallic nanofilms and nanowires.