Improved Langevin methods for spin systems

Abstract We investigate methods for variance reduction and the elimination of systematic error in a Fourier accelerated Langevin scheme for general spin models. We present results for the SU(3)×SU(3)/SU(3) model in two dimensions that are consistent with those from multi-grid methods. From a study of lattices of sizes up to 64 × 64 and for correlation lengths up to 8 lattice spacings we argue that the timing for the Langevin method makes it comparable to multi-grid for a given level of error.