Monte Carlo renormalization-group study of the d=3 planar model

The d=3 planar model is analyzed for the first time with the Monte Carlo renormalization-group (MCRG) method. To increase the efficiency of the calculation, an operator is introduced in analogy with the "vacancy" operator used in the MCRG analysis of the q=4 Potts model. This operator is shown to be important in understanding the effect of the renormalization transformation on the Hamiltonian, and in improving the convergence of the method. © 1983 The American Physical Society.