Multicritical behavior of two-dimensional anisotropic antiferromagnets in a magnetic field
arXiv:cond-mat/0702273 · doi:10.1103/PhysRevB.76.024436
Abstract
We study the phase diagram and multicritical behavior of anisotropic Heisenberg antiferromagnets on a square lattice in the presence of a magnetic field along the easy axis. We argue that, beside the Ising and XY critical lines, the phase diagram presents a first-order spin-flop line starting from T=0, as in the three-dimensional case. By using field theory we show that the multicritical point where these transition lines meet cannot be O(3) symmetric and occurs at finite temperature. We also predict how the critical temperature of the transition lines varies with the magnetic field and the uniaxial anisotropy in the limit of weak anisotropy.
21 pages, 8 figs
References in corpus (4)
- Quantum Monte Carlo study of S=1/2 weakly-anisotropic antiferromagnets on the square lattice
- Fixed point stability and decay of correlations
- Two-dimensional anisotropic Heisenberg antiferromagnet in a field
- Hidden zero-temperature bicritical point in the two-dimensional anisotropic Heisenberg model: Monte Carlo simulations and proper finite-size scaling