Journal of the Physical Society of Japan
Antiferromagnetic Triangular Ising Model with Ferromagnetic Next Nearest Neighbor Interactions –Transfer Matrix Method–
Hidetsugu Kitatani, Takehiko Oguchi
Abstract
An antiferromagnetic triangular Ising model with ferromagnetic next nearest neighbor interactions is studied by means of a transfer matrix method and a finite size scaling. Using the Roomany-Wyld approximation, it cannot be concluded definitely whether the system has only one critical point or not. By studying decays of the correlation functions of each sublattice, it is found that there is a finite temperature region where the correlation functions of each sublattice show a power law decay, namely, in this region every temperature is a critical temperature. The results by means of the present transfer matrix method are in good agreement with that by Monte Carlo methods, namely, the discrepancy between both results, reported recently, can be got rid of.