Bond chaos in the Sherrington-Kirkpatrick model

We calculate the probability distribution of the overlap between a spin glass and a copy of itself in which the bonds are randomly perturbed in varying degrees. The overlap distribution is shown to go to a delta distribution in the thermodynamic limit for arbitrarily small perturbations (bond chaos) and we obtain the scaling behaviour of the distribution with system size N in the high and low temperature phases and exactly at the critical temperature. The results are relevant for the free energy fluctuations in the Sherrington-Kirkpatrick model.