  Using dynamic cluster quantum Monte Carlo simulations, we study the
superconducting behavior of a 1/8 doped two-dimensional Hubbard model with
imposed uni-directional stripe-like charge density wave modulation. We find a
significant increase of the pairing correlations and critical temperature
relative to the homogeneous system when the modulation length-scale is
sufficiently large. With a separable form of the irreducible particle-particle
vertex, we show that optimized superconductivity is obtained for moderate
modulation strength due to a delicate balance between the modulation enhanced
pairing interaction, and a concomitant suppression of the bare
particle-particle excitations by a modulation reduction of the quasi-particle
weight.
