2014/08/31 by А. О. Сорокин, A. O. Sorokin
Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Ferromagnetism #Frustration #Heisenberg model #Ising model #Multicritical point #Phase (matter) #Phase diagram #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Renormalization group #Spins #Theoretical and Computational Physics #cond-mat.other #cond-mat.str-el #msc:82B27
paper · pdf · doi:10.1016/j.physleta.2018.10.007
published as Phys. Lett. A 382 (2018) 3455-3462 · 13 pages, 12 figures
openalex publication_date 2018/10/12 · arxiv created 2018/11/05 · arxiv updated 2018/11/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Critical behavior of three-dimensional classical frustrated antiferromagnets with a collinear spin ordering and with an additional twofold degeneracy of the ground state is studied. We consider two lattice models, whose continuous limit describes a single phase transition with a symmetry class differing from the class of non-frustrated magnets as well as from the classes of magnets with non-collinear spin ordering. A symmetry breaking is described by a pair of independent order parameters, which are similar to order parameters of the Ising and O(N) models correspondingly. Using the renormalization group method, it is shown that a transition is of first order for non-Ising spins. For Ising spins, a second order phase transition from the universality class of the O(2) model may be observed. The lattice models are considered by Monte Carlo simulations based on the Wang-Landau algorithm. The models are a ferromagnet on a body-centered cubic lattice with the additional antiferromagnetic exchange interaction between next-nearest-neighbor spins and an antiferromagnet on a simple cubic lattice with the additional interaction in layers. We consider the cases N=1,2,3 and in all of them find a first-order transition. For the N=1 case we exclude possibilities of the second order or pseudo-first order of a transition. An almost second order transition for large N is also discussed.