Correlations in the lowtemperature phase of the twodimensional XY model
Abstract
Monte Carlo simulations of the twodimensional XY model are performed in a square geometry with fixed boundary conditions. Using a conformal mapping, it is very easy to deduce the exponent η_{σ}(T) of the order parameter correlation function at any temperature in the critical phase of the model. The temperature behaviour of η_{σ}(T) is obtained numerically with a good accuracy up to the KosterlitzThouless transition temperature. At very low temperatures, a good agreement is found with Berezinskii's harmonic approximation. Surprisingly, we show some evidence that there are no logarithmic corrections to the behaviour of the order parameter density profile (with symmetrybreaking surface fields) at the KosterlitzThouless transition temperature.
 Publication:

EPL (Europhysics Letters)
 Pub Date:
 November 2002
 DOI:
 10.1209/epl/i2002002520
 arXiv:
 arXiv:condmat/0208521
 Bibcode:
 2002EL.....60..539B
 Keywords:

 05.50.+q;
 75.10.b;
 Lattice theory and statistics;
 General theory and models of magnetic ordering;
 Condensed Matter  Statistical Mechanics
 EPrint:
 7 pages, 2 eps figures