arXiv:cond-mat/0607189 · Journal of Statistical Mechanics Theory and Experiment
The three-dimensionalXYuniversality class: a high precision Monte Carlo estimate of the universal amplitude ratioA+/A−
Martin Hasenbusch B
Abstract
We simulate the improved three-dimensional two-component ϕ 4 model on the simple cubic lattice in the low and the high temperature phase for reduced temperatures down to | T − T c |/ T c ≈ 0.0017 on lattices of size up to 350 3 . Our new results for the internal energy and the specific heat are combined with the accurate estimates of β c and data for the internal energy and the specific heat at β c recently obtained in Campostrini et al (2006 Preprint cond-mat/0605083 ). We find R α = (1 − A + / A − )/α = 4.01(5), where α is the critical exponent of the specific heat and A ± is the amplitude of the specific heat in the high and the low temperature phase, respectively.