Variational study of hard-core bosons in a two-dimensional optical lattice using projected entangled pair states

We have studied the system of hard-core bosons on a two-dimensional optical lattice using a variational algorithm based on projected entangled-pair states. We have investigated the ground-state properties of the system as well as the responses of the system to sudden changes in the parameters. We have compared our results to mean-field results based on a Gutzwiller ansatz.