Abstract
We report a Monte Carlo study of the classical antiferromagnetic Heisenberg model with easy axis exchange anisotropy on the triangular lattice. Both the free energy cost for long-wavelength spin waves as well as for the formation of free vortices are obtained from the spin stiffness and vorticity modulus, respectively. Evidence for two distinct Kosterlitz-Thouless types of defect-mediated phase transitions at finite temperatures is presented.
- Received 23 November 1999
DOI:https://doi.org/10.1103/PhysRevB.61.11514
©2000 American Physical Society