  The isotropic, non-magnetic doped BaBiO$_3$ superconductors maintain some
similarities to high-Tc cuprates, while also providing a cleaner system for
isolating charge density wave (CDW) physics that commonly competes with
superconductivity. Artificial layered superlattices offer the possibility of
engineering the interaction between superconductivity and CDW. Here we
stabilize a low temperature, fluctuating short range CDW order by using
artificially layered epitaxial (BaPbO$_3$)$_{3m}$/(BaBiO$_3$)$_m$ (m = 1-10
unit cells) superlattices that is not present in the optimally doped
BaPb$_{0.75}$Bi$_{0.25}$O$_3$ alloy with the same overall chemical formula.
Charge transfer from BaBiO$_3$ to BaPbO$_3$ effectively dopes the former and
suppresses the long range CDW, however as the short range CDW fluctuations
strengthens at low temperatures charge appears to localize and
superconductivity is weakened. The monolayer structural control demonstrated
here provides compelling implications to access controllable, local
density-wave orders absent in bulk alloys and manipulate phase competition in
unconventional superconductors.
