{ "id": "cond-mat/0412355", "version": "v1", "published": "2004-12-14T11:42:20.000Z", "updated": "2004-12-14T11:42:20.000Z", "title": "Ising model in scale-free networks: A Monte Carlo simulation", "authors": [ "Carlos P. Herrero" ], "comment": "5 pages, 5 figures", "journal": "Phys. Rev. E 69, 067109 (2004)", "doi": "10.1103/PhysRevE.69.067109", "categories": [ "cond-mat.stat-mech" ], "abstract": "The Ising model in uncorrelated scale-free networks has been studied by means of Monte Carlo simulations. These networks are characterized by a degree (or connectivity) distribution $P(k) \\sim k^{-\\gamma}$. The ferromagnetic-paramagnetic transition temperature has been studied as a function of the parameter $\\gamma$. For $\\gamma > 3$ our results agree with earlier analytical calculations, which found a phase transition at a temperature $T_c(\\gamma)$ in the thermodynamic limit. For $\\gamma \\leq 3$, a ferromagnetic-paramagnetic crossover occurs at a size-dependent temperature $T_{co}$, and the system is in the ordered ferromagnetic state at any temperature for a system size $N \\to \\infty$. For $\\gamma = 3$ and large enough $N$, the crossover temperature is found to be $T_{co} \\approx A \\ln N$, with a prefactor $A$ proportional to the mean degree. For $2 < \\gamma < 3$, we obtain $T_{co} \\sim < k > N^z$, with an exponent $z$ that decreases as $\\gamma$ increases. This exponent is found to be lower than predicted by earlier calculations.", "revisions": [ { "version": "v1", "updated": "2004-12-14T11:42:20.000Z" } ], "analyses": { "keywords": [ "monte carlo simulation", "scale-free networks", "ising model", "ferromagnetic-paramagnetic transition temperature", "ferromagnetic-paramagnetic crossover occurs" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Phys. Rev. E" }, "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable" } } }