Tunneling spectroscopy of superconducting nanospheres

Abstract

Energy spectra of superconducting nanospheres observed via tunneling spectroscopy are theoretically discussed. In the energy gap we find small peaks which correspond to the two-particle dynamics beyond the mean-field BCS approximation.

These peaks promise to be a sensitive test of theories of superconductivity as their number and positions depend on the approximation used.

Keywords

• ultrasmall metallic grains
• discrete electronic states
• energy-spectrum
• mercury films
• nanoclusters
• nanoparticles
• particles