Green's Function Monte Carlo study of correlation functions in the   (2+1)D U(1) lattice gauge theory
  A ``forward walking'' Quantum Monte Carlo (QMC) algorithm has been developed to calculate correlation functions for the Hamiltonian lattice formulation of U(1) Yang-Mills theory in (2+1) dimensions. It is shown that Wilson loops can be calculated with high accuracy. Creutz ratios are used to determine the string tension, which agrees with results from other approaches. Timelike correlations are used to estimate the mass gaps, which agree with series expansion results in the strong coupling regime. 
Chris J. Hamer, Robert J. Bursill and Maria Samaras