  Ultracold ground state dipolar 40K-87Rb molecules have recently been produced
in a loose harmonic trap by employing a magnetic field sweep across a Feshbach
resonance followed by stimulated Raman adiabatic passage [K.-K. Ni et al.,
Science 322, 231 (2008)]. The overall experimental efficiency for molecule
formation was around 20%. We show that the efficiency can be increased to
nearly 100% if one first loads the atomic gases into an optical lattice of the
appropriate depth and tunes the interspecies attraction to have exactly one
atom of each species at an occupied lattice site. Our proposed scheme provides
a large enhancement to the dipolar molecule density even at relatively high
temperatures, and avoids three-body recombination loss by preventing lattice
sites from being triply occupied.
