Site dilution in the fully frustrated triangular lattice in two dimensions

Abstract

The “Transfermatrix-Method” [1, 2] has been adapted to evaluate also the free energy of triangular 2−d-Ising lattices. The present work considers a model with nearest-neighbour antiferromagnetic couplings and a fraction 1−x of spins removed at random sites leading to some frustration effects. It is not yet clear if such a system shows spinglass behaviour [3, 4]. The correlation function 〈s ₀ s _R 〉² (correlation between two spins with distanceR), which is related to the Edwards-Anderson-Orderparameter, shows such a fast breakdown with distanceR that there is a clear evidence against a phase transition at finiteT. In contrast to other models [1, 2, 5] we still expect an exponential decay of {〈s ₀ s _R 〉²} _av with distanceR atT=0.