EFFECTS OF PERCOLATION ON SPIN GLASS ORDER

The authors investigate, using Migdal's recursion relations, a simple model which exhibits both spin glass and percolation behaviour. At zero temperature the spin glass phase occurs even for a very small fraction of negative interactions if the system is sufficiently dilute that it is close to the percolation threshold. Crossover away from percolation behaviour induced by adding a small fraction of negative bonds at zero temperature is characterised by a crossover exponent of unity independent of spatial dimension which is probably an exact result.