Ordered vs Disordered: Correlation Lengths of 2D Potts Models at \beta_t

Abstract

We performed Monte Carlo simulations of two-dimensional $q$-state Potts models with $q=10,15$, and $20$ and measured the spin-spin correlation function at the first-order transition point ${\beta }_t$ in the disordered and ordered phase. Our results for the correlation length ${\xi }_d({\beta }_t)$ in the disordered phase are compatible with an analytic formula. Estimates of the correlation length ${\xi }_o({\beta }_t)$ in the ordered phase yield strong numerical evidence that $R\equiv {\xi }_o({\beta }_t)/{\xi }_d({\beta }_t)=1$.

Comments: 3 pages, uuencoded compressed postscript file, contribution to the LATTICE'94 conference