EXCITATION MORPHOLOGY OF SHORT-RANGE ISING SPIN-GLASSES

We numerically examine Ising spin-glass models, with lattice sizes up to 32(3) in 3D and 256(2) in 2D. A good local minimum PSI is initially found, and used as a reference state. The phase-space of the system in a neighborhood of PSI is sampled by first generating an excited state with energy b measured from PSI and by then quenching the system to a new local energy minimum PSI'. Connected clusters of spins which differ in the two configurations are identified. The dependence of their number, size and energy on b is shown to be systematic. It can be described in terms of simple functions for sufficiently low b. We find in addition a transition to a high b regime, where the behavior of the above quantities is qualitatively different. The dynamical consequences of our results, in particular the thermal metastability properties, are discussed in some detail.