Low-temperature spin-glass behaviour in a diluted dipolar Ising system

Abstract

Using Monte Carlo simulations, we study the character of the spin-glass (SG) state of a site-diluted dipolar Ising model. At high dilution, well deep in the SG phase, we find spiky distributions that are strongly sample-dependent. For the system sizes studied, the average width of spikes,and the fraction of samples with spikes higher than a certain threshold does not vary appreciably with system size. These results are at odds with crucial predictions of the droplet and RSB scenarios. Our findings are similar to the ones found for the short-ranged Edwards-Anderson model.