title: Magnetic phase diagrams of classical triangular and kagome antiferromagnets.
abstract: We investigate the effect of geometrical frustration on the H-T phase diagrams of the classical Heisenberg antiferromagnets on triangular and kagome lattices. The phase diagrams for the two models are obtained from large-scale Monte Carlo simulations. For the kagome antiferromagnet, thermal fluctuations are unable to lift degeneracy completely and stabilize translationally disordered multipolar phases. We find a substantial difference in the temperature scales of the order by disorder effect related to different degeneracy of the low- and the high-field classical ground states in the kagome antiferromagnet. In the low-field regime, the Kosterlitz-Thouless transition into a spin-nematic phase is produced by unbinding of half-quantum vortices.
authors.affiliation: Department of Physics, Kharkov National University, 61077 Kharkov, Ukraine.
authors.forename: M V
authors.initials: MV
authors.lastname: Gvozdikova
authors.forename: P-E
authors.initials: PE
authors.lastname: Melchy
authors.forename: M E
authors.initials: ME
authors.lastname: Zhitomirsky