Tuning the quantum phase transition of bosons in optical lattices via periodic modulation of the s-wave scattering length.

We consider interacting bosons in a two-dimensional square and a three-dimensional cubic optical lattice with a periodic modulation of the s-wave scattering length. At first we map the underlying periodically driven Bose-Hubbard model for large enough driving frequencies approximately to an effective time-independent Hamiltonian with a conditional hopping. Combining different analytical approaches with quantum Monte Carlo simulations then reveals that the superfluid-Mott-insulator quantum phase transition still exists despite the periodic driving and that the location of the quantum phase boundary turns out to depend quite sensitively on the driving amplitude. A more detailed quantitative analysis shows that the effect of driving can even be described within the usual Bose-Hubbard model provided that the hopping is rescaled appropriately with the driving amplitude. [ABSTRACT FROM AUTHOR]