摘要
Advanced Monte Carlo simulations of magnetisation and susceptibility in 3D XY model are performed at two different coupling constantsβ=0.55 andβ=0.5,completing our previous simulation results with additional data points and extending the range of the external field to twice as small values as previously reported(h≥0.00015625).The simulated maximal lattices sizes are also increased from L=384 to L=512.Our aim is an improved estimation of the exponentρ,describing the Goldstone mode singularity M(h)=M(+0)+chρat h→0,where M is the magnetisation.The data reveal some unexpected small oscillations.It makes the estimation by manyparameter fits of the magnetisation data unstable,and we are looking for an alternative method.Our best estimateρ=0.555(17)is extracted from the analysis of effective exponents determined from local fits of the susceptibility data.This method gives stable and consistent results for both values ofβ,taking into account the leading as well as the subleading correction to scaling.We report also the values of spontaneous magnetisation.
