EVIDENCE FOR A WEAK FIRST-ORDER TRANSITION IN THE QUASI-ONE-DIMENSIONAL FRUSTRATED XY-ANTIFERROMAGNET

The results of a finite-size scaling analysis of histogram Monte Carlo simulations on the stacked triangular XY-antiferromagnet with anisotr opic near-neighbour exchange interactions are presented. With ferromag netic interplane coupling ten rimes stronger than the antiferromagneti c intraplane interaction (J(parallel to)/J(perpendicular to) = -10), a weak first-order transition is revealed. These results represent 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 behaviour in this and similar frustrated systems, and have particular relevance to recen tly reported data on CsCuCl3.