  While bulk bismuth (Bi) is a semimetal, we have found clear evidence of
superconductivity in a crystalline 72 nm diameter Bi nanowire below 1.3 K. In a
parallel magnetic field (H), the residual resistance of the nanowire below Tc
displays periodic oscillations with H, and the period corresponds to the
superconducting flux quantum. This result provides evidence that the
superconductivity comes from the interface shell between Bi and the surface
oxide. In a perpendicular H, the resistance in the superconducting state shows
Shubnikov-de Haas (SdH) oscillations, a signature of a normal metal. These
results indicate a novel coexistence of Bosonic and Fermionic states in the
surface shell of nanowires.
