Particle-hole pair excitations in Mott insulator quench dynamics

We investigate the dynamics of strongly interacting bosons in an optical lattice in a quantum quench scenario where we start from a Mott insulator state and suddenly raise the lattice depth. Despite the nature of short-range coherence in the Mott state, we find that the coherence visibility exhibits collapse and revival oscillations which could be observed in experiments. The quasi-momentum distribution oscillates between a maximum occupation at $k=0$ (during revivals) and $k=\pi$ (during collapse). We show that the $k=\pi$ revivals are caused by the presence of particle-hole pair excitations on top of a constant Mott background. We further show that similar effects are found in other lattice models such as with fermions and Bose-Fermi mixtures. We provide a general framework and point to a new avenue to probe strongly correlated many-body states going beyond the superfluid paradigm of collapse and revivals.