Eur. Phys. J. B 70, 435-441 (2009)
https://doi.org/10.1140/epjb/e2009-00240-2

Antiferromagnetic Ising model in scale-free networks

Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain

Corresponding author: ^a ch@icmm.csic.es

Received: 10 March 2009
Revised: 15 June 2009
Published online: 15 July 2009

Abstract

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^-γ. 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 γ and the minimum degree present in the networks. T_c is found to increase when the exponent γ is reduced, in line with a larger frustration caused by the presence of nodes with higher degree.