Search for a transition in the three-dimensional J Ising spin-glass

The three-dimensional Ising spin-glass in zero field with nearest-neighbor interactions having ±J distribution is studied by Monte Carlo simulations for samples of linear dimension L with 3≤L≤20. Results for the probability distribution, PL(q), of the spin-glass order parameter are analyzed by finite-size scaling. Data for T1.2 are consistent with a conventional phase transition at Tc=1.2-0.2+0.1, with exponents ν=1.3±0.3 and η=-0.3±0.2. However, results at lower temperature indicate marginal behavior and suggest that the lower critical dimensional is close to three.