Tensor-network study of correlation-spreading dynamics in the two-dimensional Bose-Hubbard model

We analyze real-time dynamics of the two-dimensional Bose-Hubbard model after a sudden quench starting from the Mott insulator by means of the two-dimensional tensor-network method. Calculated single-particle correlation functions are found to be in good agreement with a recent experiment [Y. Takasu {it et al.}, Sci. Adv. {bf 6}, eaba9255 (2020)], which cross validates the experiment and the numerical simulation. By estimating the phase and group velocities from the single-particle and density-density correlation functions, we predict how these velocities vary in the moderate interaction region, which will be useful for future experiments.