  We carry out a microscopic study of a vortex lattice in a strongly
correlated, type-II, d-wave superconductor(SC) using Bogoliubov de Gennes (BDG)
formalism. In weak-coupling theory, commonly accepted truism is that a vortex
binds to impurity. We demonstrate that in unconventional SCs, the binding of
vortex to an impurity depends on relevant parameters. In particular, we
illustrate such dependency on the sign of impurity, i.e. attractive or
repulsive, as well as doping. We emphasize that this seemingly unanticipated
behavior arises from strong correlation effects and is absent in weak coupling
descriptions.
