  We report $T=0$ diffusion Monte Carlo results for the ground-state and vortex
excitation of unpolarized spin-1/2 fermions in a two-dimensional disk. We
investigate how vortex core structure properties behave over the BEC-BCS
crossover. We calculate the vortex excitation energy, density profiles, and
vortex core properties related to the current. We find a density suppression at
the vortex core on the BCS side of the crossover, and a depleted core on the
BEC limit. Size-effect dependencies in the disk geometry were carefully
studied.
