https://doi.org/10.1007/s100510050729
Ground-state landscape of 2d ± J Ising spin glasses
Institut für Theoretische Physik, Heidelberg, Germany
Received:
12
October
1998
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
