  The preparation of a quantum degenerate gas of heteronuclear molecules has
been an outstanding challenge. We use path integral Quantum Monte Carlo
simulations to understand the role of interactions and finite temperature
effects in the protocol currently employed to adiabatically prepare a
low-entropy gas of polar molecules in a lattice starting from an ultracold
Bose-Fermi mixture. We find that interspecies interactions affect the final
temperature of the mixture after the adiabatic loading procedure and
detrimentally limit the molecular peak filling. Our conclusions are in
agreement with recent experimental measurements [1] and therefore are of
immediate relevance for the myriad experiments that aim to form molecules from
dual-species atomic gases.
