  The Kondo effect and superconductivity are both prime examples of many-body
phenomena. Here we report transport measurements on a carbon nanotube quantum
dot coupled to superconducting leads that show a delicate interplay between
both effects. We demonstrate that the superconductivity of the leads does not
destroy the Kondo correlations on the quantum dot when the Kondo temperature,
which varies for different single-electron states, exceeds the superconducting
gap energy.
