Ising Transition Driven by Frustration in a 2D Classical Model with Continuous Symmetry
Abstract
We study the thermal properties of the classical antiferromagnetic Heisenberg model with both nearest (J1) and next-nearest (J2) exchange couplings on the square lattice by extensive Monte Carlo simulations. We show that, for J2/J1>1/2, thermal fluctuations give rise to an effective Z2 symmetry leading to a finite-temperature phase transition. We provide strong numerical evidence that this transition is in the 2D Ising universality class, and that Tc→0 with an infinite slope when J2/J1→1/2.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 2003
- DOI:
- 10.1103/PhysRevLett.91.177202
- arXiv:
- arXiv:cond-mat/0307431
- Bibcode:
- 2003PhRvL..91q7202W
- Keywords:
-
- 75.10.Hk;
- 75.40.Cx;
- 75.40.Mg;
- Classical spin models;
- Static properties;
- Numerical simulation studies;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Statistical Mechanics
- E-Print:
- 4 pages with 4 figures