PHASE-TRANSITIONS IN THE CLASSICAL XY ANTIFERROMAGNET ON THE TRIANGULAR LATTICE

The critical behaviour of the hilly frustrated classical antiferromagn et on the triangular lattice is studied using Monte Carlo methods. Num erical evidence for separate Kosterlitz-Thouless and Ising transitions is presented as a result of investigating the free-energy cost to cre ate an isolated vortex, the finite-size scaling of the spin stiffness and the finite-size scaling of the chirality.