Amplitude Effects in Lattice Modulation Spectroscopy

Linear-response calculations for a periodically modulated optical lattice depth within the Mott-insulating phase of the Hubbard model clearly predict a resonance in the doublon production rate at the Hubbard repulsion U. Using a recently developed strong-coupling approach, we examine the effect of an increasingly high amplitude of the modulation. We find that multi-quanta excitations are likely to occur beyond a certain threshold.