Aging behavior of spin glasses under bond and temperature perturbations from laser illumination

We have studied the nonequilibrium dynamics of spin glasses subjected to bond perturbation, which was based on the direct change in the spin-spin interaction ΔJ, using photoillumination in addition to temperature change ΔT. Differences in time-dependent magnetization are observed between that under ΔT+ΔJ and ΔT perturbations with the same ΔT. These differences show the contribution of ΔJ to spin-glass dynamics through the decrease in the overlap length. That is, the overlap length LΔT+ΔJ under ΔT+ΔJ perturbation is less than LΔT under ΔT perturbation. Furthermore, we observe the crossover between weakly and strongly perturbed regimes under bond cycling accompanied by temperature cycling. These effects of bond perturbation strongly indicate the existence of both chaos and the overlap length.