Ising model on mixed two-dimensional lattices

We inform results on physical and topological magnitudes related to the ground level of Ising model on mixed two-dimensional lattices of coordination numbers 4 (Kagome lattices) and 5 (five-point star lattices). We consider little clusters of size N, where N represents the total number of spins, subject to periodic boundary conditions. On these systems we randomly distribute +/-J nearest-neighbor interactions (+J: antiferromagnetic, -J: ferromagnetic (F)). Concentration x of F interactions is varied in the interval (0, 1). Two different methods are used to obtain results reported here. First, a numerical method related to multiple replicas. Second, an analytical method based on probabilistic analysis of flat and curved plaquettes. Both methods are complementary to each other. Initially, this study is restricted to calculate frustration of plaquettes and bonds, energy and bond order parameter at T = 0. The results of magnitudes informed here are compared with the similar ones obtained for honeycomb, square and triangular lattices. (C) 2002 Elsevier Science B.V. All rights reserved.