Weak first-order transition in the quasi-one-dimensional frustrated XY antiferromagnet

The results of finite-size scaling analysis of histogram Monte-Carlo simulations on the stacked triangular XY antiferromagnet with anisotropic near-neighbor exchange interactions are presented. With ferromagnetic interplane coupling ten times stronger than the antiferromagnetic intraplane interaction ($J_\| / J_\bot = -10$), a weak first-order transition is revealed. These results represents the first simulational corroboration of a wide variety of renormalization-group calculations made over the past twenty years. As such, they shed light on recent controversy regarding the critical behavior in this and similar frustrated systems and have particular relevance to recently reported data on $CsCuCl_3$.