Dresden 2003 – scientific programme
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DY: Dynamik und Statistische Physik
DY 12: Statistical physics of complex networks
DY 12.4: Talk
Monday, March 24, 2003, 12:15–12:30, G\"OR/226
Ferromagnetic Phase Transition in a Scale-free Network — •Janusz Holyst1,2, Agata Fronczak1,2, and Dietrich Stauffer2 — 1Faculty of Physics and Center of Excellence for Complex Systems Research, Warsaw University of Technology, Koszykowa 75, PL-00-662 Warsaw, Poland — 2Institute for Theoretical Physics, Cologne University, D-50923 Koeln, Germany
Ising spins put onto a Barabasi-Albert scale-free network show an effective phase transition from ferromagnetism to paramagnetism upon heating, with an effective critical temperature increasing as the logarithm of the system size. Starting with all spins up and upon equilibration pinning the few most-connected spins down nucleates the phase with most of the spins down. Mean field calculations for this model are presented.
References. A. Aleksiejuk, J.A. Holyst and D. Stauffer, No-dqFerromagnetic Phase Transition in Barabasi-Albert NetworksNo-dq, PHYSICA A 310 (1-2), 260-266 (2002)