2008/04/30 by N. G. Fytas, Nikolaos G. Fytas, A. Malakis +2 · 1 citation
Physics and Astronomy · #Complex Network Analysis Techniques #Opinion Dynamics and Social Influence #Theoretical and Computational Physics #cond-mat.dis-nn #cond-mat.stat-mech
paper · pdf · doi:10.1088/1742-5468/2008/07/l07001
published as J. Stat. Mech. (2008) L07001 · 9 pages, 3 figures, version as accepted for publication
arxiv created 2008/07/10 · openalex publication_date 2008/07/24 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/07/30
We report results from a Wang–Landau study of the random bond square Ising model with nearest-neighbor ( J nn ) and next-nearest-neighbor ( J nnn ) antiferromagnetic interactions. We consider the case R = J nn / J nnn = 1 for which the competitive nature of interactions produces a sublattice ordering known as superantiferromagnetism and the pure system undergoes a second-order transition with a positive specific heat exponent α. For a particular disorder strength we study the effects of bond randomness and we find that, while the critical exponents of the correlation length ν, magnetization β, and magnetic susceptibility γ increase as compared to the pure model, the ratios β/ν and γ/ν remain unchanged. Thus, the disordered system obeys weak universality and hyperscaling similarly to other two-dimensional disordered systems. However, the specific heat exhibits an unusually strong saturating behavior which distinguishes the present case of competing interactions from other two-dimensional random bond systems studied previously.