arXiv:0810.2716 · Journal of Statistical Mechanics Theory and Experiment
A Monte Carlo study of the three-dimensionalXYuniversality class: universal amplitude ratios
Martin Hasenbusch
Abstract
We simulate lattice models in the three-dimensional XY universality class in the low and the high temperature phase. In addition to the XY model, we study the three-dimensional two-component ϕ 4 model on the simple cubic lattice. The parameter of the ϕ 4 model is chosen such that leading corrections to scaling are small. This allows us to compute a number of universal amplitude ratios with unprecedented precision: R ϒ = 0.411(2), R B = 2.83(1), R ξ + = 0.3562(10) and R ξ − = 0.850(5). These results can be compared with those obtained from other theoretical methods, such as field theoretic methods or the high temperature series expansion and also with experimental results for the λ-transition of 4 He.