Ground-state landscape of 2d ± J Ising spin glasses
Institut für Theoretische Physik, Heidelberg, Germany
Published online: 15 April 1999
Large numbers of ground states of two-dimensional Ising spin glasses with periodic boundary conditions in both directions are calculated for sizes up to 402. A combination of a genetic algorithm and Cluster-Exact Approximation is used. For each quenched realization of the bonds up to 40 independent ground states are obtained. For the infinite system a ground-state energy of is extrapolated. The ground-state landscape is investigated using a finite-size scaling analysis of the distribution of overlaps. The mean-field picture assuming a complex landscape describes the situation better than the droplet-scaling model, where for the infinite system mainly two ground states exist. Strong evidence is found that the ground states are not organized in an ultrametric fashion in contrast to previous results for three-dimensional spin glasses.
PACS: 75.10.Nr – Spin glasses and other random models / 75.40.Mg – Numerical simulation studies / 02.10.Jf – General mathematical systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999