Improved extremal optimization for the Ising spin glass

A version of the extremal optimization (EO) algorithm introduced by Boettcher and Percus is tested on two- and three-dimensional spin glasses with Gaussian disorder. EO preferentially flips spins that are locally “unfit”; the variant introduced here reduces the probability of flipping previously selected spins. Relative to EO, this adaptive algorithm finds exact ground states with a speedup of order 10⁴  (10²) for 16²‐  (8³‐)spin samples. This speedup increases rapidly with system size, making this heuristic a useful tool in the study of materials with quenched disorder.