Antiferromagnetic Ising model in scale-free networks

The antiferromagnetic Ising model in uncorrelated scale-free networks has been studied by means of Monte Carlo simulations. These networks are characterized by a connectivity (or degree) distribution P(k) ~ k^(- gamma). The disorder present in these complex networks frustrates the antiferromagnetic spin ordering, giving rise to a spin-glass (SG) phase at low temperature. The paramagnetic-SG transition temperature T_c has been studied as a function of the parameter gamma and the minimum degree present in the networks. T_c is found to increase when the exponent gamma is reduced, in line with a larger frustration caused by the presence of nodes with higher degree.