Physical Review Letters
Relation of Random and Competing Nonrandom Couplings for Spin-Glasses
Fritz Haake, Maciej Lewenstein, Martin Wilkens
Abstract
By mapping the Edwards-Anderson model onto a nonrandom Ising model we argue that the lower critical dimension ${d}^{*}$ for the Edwards-Anderson spin-glass is close to 3 and may depend on the probability distribution of the bond strengths. For $d>{d}^{*}$, the approach to spin-glass order from the paramagnetic phase is characterized by Ising exponents. At $d={d}^{*}$, however, the critical exponents defined for $T>{T}_{c}$ are twice the corresponding Ising ones. These results are consistent with recent computer simulations.