Weber C Capriotti L Misguich G Becca F Elhajal M Mila F 2003 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 T(c)-->0 with an infinite slope when J2/J1-->1/2. application/pdf https://sonar.ch/global/documents/93668 eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevLett.91.177202 info:eu-repo/semantics/altIdentifier/pmid/14611373 info:eu-repo/semantics/openAccess Physical review letters. - 2003 General Physics and Astronomy Ising transition driven by frustration in a 2D classical model with continuous symmetry. http://purl.org/coar/resource_type/c_6501