Regensburg 2004 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.89: Poster

Donnerstag, 11. März 2004, 16:00–18:00, Poster D

Short-Time Dynamics — •Eric Lorenz and Wolfhard Janke — Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig, Germany

The 2d Ising model on a square lattice is quenched from a state at high temperature to the critical temperature and its dynamic relaxation is investigated with Monte Carlo methods. In the case of a small initial magnetization, a critical initial increase of the magnetization is observed during early time of the dynamic evolution. With power laws derived from the scaling relation being valid already in non-equilibrium, one can determine estimates for the critical exponents θ, z, and β/ν. This procedure of observing quantities in non-equilibrium prevents critical slowing down caused by the divergence of the spatial correlation length at the critical temperature in equilibrium. In this work special attention is paid to a comparison of algorithms. The dynamics produced by heat-bath, Metropolis and Glauber updates are found to be universal, despite surprising differences during the very early time evolution, which are investigated in some detail.