Universal Jump in the Helicity Modulus of the Two-Dimensional Quantum XY Model
arXiv:cond-mat/9702081 · doi:10.1103/PhysRevB.55.R11949
Abstract
The helicity modulus of the S=1/2 XY model is precisely estimated through a world line quantum Monte Carlo method enhanced by a cluster update algorithm. The obtained estimates for various system sizes and temperatures are well fitted by a scaling form with L replaced by \log(L/L_0), which is inferred from the solution of the Kosterlitz renormalization group equation. The validity of the Kosterlitz-Thouless theory for this model is confirmed.
4 pages, 3 figures