Multioverlap simulations of the 3D Edwards-Anderson Ising spin glass

We introduce a novel method for numerical spin glass investigations: Simulations of two replica at fixed temperature, weighted to achieve a broad distribution of the Parisi overlap parameter q (multioverlap). We demonstrate the feasibility of the approach by studying the 3D Edwards-Anderson Ising (J(ik) = +/-1) spin glass in the broken phase (beta = 1). This makes it possible to obtain reliable results about spin glass tunneling barriers. In addition, our results indicate a nontrivial scaling behavior of the canonical q distributions not only at the freezing point but also deep in the broken phase.