Universality in the partially anisotropic three-dimensional Ising lattice
M. A. Yurishchev
Abstract
Using transfer-matrix extended phenomenological renormalization-group methods the critical properties of spin-1/2 Ising model on a simple-cubic lattice with partly anisotropic coupling strengths J = (J ′,J ′,J) are studied. Universality of both fundamental critical exponents yt and yh is confirmed. It is shown that the critical finite-size scaling amplitude ratios U = A χ (4)Aκ/A 2 χ, Y1 = A κ ′′/Aχ, and Y2 = A κ (4)/A χ (4) are independent of the lattice anisotropy parameter ∆ = J ′ /J. By this for the last above invariant of the threedimensional Ising universality class we give the first quantitative estimate: Y2 ≃ 2.013 (shape L × L × ∞, periodic boundary conditions in both transverse directions). PACS numbers: 05.50.+q, 05.70.Jk, 64.60.Fr, 75.10.Hk 1 1