The response to dynamical modulation of the optical lattice for fermions   in the Hubbard model
  Fermionic atoms in a periodic optical lattice provide a realization of the single-band Hubbard model. Using Quantum Monte Carlo simulations along with the Maximum Entropy Method, we evaluate the effect of a time-dependent perturbative modulation of the optical lattice amplitude on atomic correlations, revealed in the fraction of doubly-occupied sites. Our treatment extends previous approaches which neglected the time dependence of the on-site interaction, and shows that this term changes the results in a quantitatively significant way. The effect of modulation depends strongly on the filling-- the response of the double occupation is significantly different in the half-filled Mott insulator from the doped Fermi liquid region. 
Zhaoxin Xu, Simone Chiesa, Shuxiang Yang, Shi-Quan Su, Daniel E.   Sheehy, Juana Moreno, Richard T. Scalettar, and Mark Jarrell
cond-mat.quant-gas