Phase Transition in the Two Dimensional Classical XY Model

Abstract

For the two dimensional classical XY model we present extensive high -temperature -phase bulk data extracted based on a novel finite size scaling (FSS) Monte Carlo technique, along with FSS data near criticality. Our data verify that $\eta =1/4$ sets in near criticality, and clarify the nature of correction to the leading scaling behavior. However, the result of standard FSS analysis near criticality is inconsistent with other predictions of Kosterlitz's renormalization group approach.

Comments: Significant changes in the text and the figures. To appear in Phys. Lett. A Hard copies of seven figures are available upon request