physica status solidi (b)
Computational Evidence for the Transition Point of a Square Ising Lattice with First and Second Neighbour Interactions
W. Bitterlich, Rainer J. Jelitto
Abstract
Abstract From numerical calculations for a toroidally closed Ising lattice of finite diameter it is seen that it is possible to obtain the transition point of a square Ising lattice with nearest and next‐nearest neighbour interactions to a high degree of accuracy. In the case of a lattice with pure nearest neighbour interactions the curves of the internal energy for all diameters of the torus intersect in one point, which is the transition point of the infinite lattice. When next‐nearest neighbour coupling is present, this is no longer exactly valid, but the dependence of the situation of the different points of intersection on the diameter is so exceedingly weak that a rapid convergence to the Curie point may be assumed with increasing size of the lattice and the transition point can be deduced thereby. The assumptions involved in this method and its consequences are discussed and the result of the investigation is compared with a theory of Vaks et al., which deals with a similar type of interaction.