Multi-overlap simulations of free-energy barriers in the 3D Edwards–Anderson Ising spin glass

We report large-scale simulations of the three-dimensional Edwards–Anderson Ising spin-glass model using the multi-overlap Monte Carlo algorithm. We present our results in the spin-glass phase on free-energy barriers and the non-trivial finite-size scaling behavior of the Parisi order-parameter distribution.  1999 Elsevier Science B.V. All rights reserved. Spin-glass systems [1] are simple models of disordered materials such as, e.g., (Fe0.15Ni0.85)75P16B6Al3 [2], with randomly distributed, competing interactions. Analytical solutions are only known in the mean-field limit which corresponds to infinite dimensionality or, equivalently, infinite-range interactions. For the physical case of short-ranged spin glasses in three dimensions this may serve as a guideline, but for quantitative predictions we have to rely either on numerical methods such as Monte Carlo (MC) simulations or high-temperature series expansions [3]. The prototype model is the Edwards–Anderson Ising (EAI) spin glass whose energy is given by