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DY: Dynamik und Statistische Physik

DY 42: Critical Phenomena and Phase Transitions II

DY 42.4: Vortrag

Donnerstag, 30. März 2006, 11:45–12:00, H\"UL 186

Free-Energy Barriers in a Mean-Field Spin Glass — •Elmar Bittner and Wolfhard Janke — Institut für Theoretische Physik, Universität Leipzig, Postfach 100 920, 04009 Leipzig, Germany

The mean-field Sherrington-Kirkpatrick spin-glass model is investigated by means of Monte Carlo simulations employing multioverlap and parallel tempering methods. We investigate the finite-size scaling behaviour of the free-energy barriers which are visible in the probability density of the Parisi overlap parameter. Assuming that the mean barrier height diverges with the number of spins N as N^α, our data show good agreement with the theoretical value α = 1/3. We also found that the free-energy barriers of the Sherrington-Kirkpatrick spin-glass model are non-self-averaging and distributed according to the Fréchet extremal value distribution.