  Recent scanning tunneling microscopy measurements on cuprate superconductors
have revealed remarkable spatial inhomogeneities in the single-particle energy
gap. Using cellular dynamical mean-field theory, we study the zero temperature
superconducting properties of a single-band Hubbard model with a spatial
modulation of the electron density. We find that the inhomogeneity in the
electronic structure results in a substantial spatial variation in the
superconducting order parameter and single-particle energy gap, reminiscent of
the experimental results. In particular, we find that the order parameter and
gap amplitudes in the hole-rich regions are significantly enhanced over the
corresponding quantities in a uniform system, if the hole-rich regions are
embedded in regions with smaller hole density.
