On the universal behavior of two-dimensional Ising spin glasses

Ising spin glasses are studied, at zero temperature, on a hierarchical latt ice as an approach to the square lattice. The stiffness exponent y, which g overns the behavior of the interactions under changes of scale, is computed for several distinct continuous symmetric probability distributions for th e couplings. All distributions considered lead to the same estimates, i.e., the exponent y is universal. Our results are compared with other estimates available for the two-dimensional Gaussian Ising spin glass. (C) 2000 Else vier Science B.V. All rights reserved.