Variational study of a mobile hole in a two dimensional quantum antiferromagnet using entangled-plaquette states

We study the properties of a mobile hole in the $t-J$ model on the square lattice by means of variational Monte Carlo simulations based on the entangled-plaquette ansatz. Our energy estimates for small lattices reproduce available exact results. We obtain values for the hole energy dispersion curve on large lattices in quantitative agreement with earlier findings based on the most reliable numerical techniques. Accurate estimates of the hole spectral weight are provided.