Light-cone like spreading of single-particle correlations in the   Bose-Hubbard model after a quantum quench in the strong coupling regime
  We study the spreading of correlations in space and time after a quantum quench in the Bose Hubbard model. We derive equations of motion for the single-particle Green's function within the contour-time formalism, allowing us to study dynamics in the strong coupling regime. We discuss the numerical solutions of these equations and calculate the single-particle density matrix for quenches in the Mott phase. We demonstrate light-cone like spreading of correlations in the Mott phase in one, two, and three dimensions and calculate propagation velocities in each dimension. 
Matthew R. C. Fitzpatrick, Malcolm P. Kennett
cond-mat.quant-gas cond-mat.str-el