Monte carlo study of the order-parameter distribution in the four-dimensional ising spin glass

We investigate the order-parameter distribution P(q) of the Ising spin glass with nearest-neighbor interactions in four dimensions using Monte Carlo simulations on lattices of linear dimension up to L=6. We find that, below the transition temperature Tc, the weight at small q seems to saturate to a nonzero value as the size increases, similar to the infinite-range Sherrington- Kirkpatrick model. We discuss our results in the light of recent theoretical predictions for the nature of the spin-glass phase.