Dresden 2003 – wissenschaftliches Programm
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SYSE: Simulation and experiment
SYSE 2: Poster (gemeinsam mit SYCN und CPP)
SYSE 2.26: Poster
Dienstag, 25. März 2003, 19:00–21:00, ZEU/250
How long does a ± J Edwards-Anderson spin glass need to reach equilibrium? — •Sigismund Kobe1, Jarosław Krawczyk1,2, and Alexander K. Hartmann3 — 1Institut für Theoretische Physik, Technische Universität Dresden, D-01062 Dresden — 2Institut für Theoretische Physik, Technische Universität Clausthal, D-38678 Clausthal-Zellerfeld — 3Institut für Theoretische Physik, Universität Göttingen D-37073 Göttingen
Glassy systems are characterized by a slowing down of dynamical processes at low temperatures due to a complex structure of the underlying (free) energy landscape. Here, the process of approaching the equilibrium of ± J Edwards-Anderson spin-glass models is studied, where L × L × L spins are placed on a cubic lattice with periodic boundary conditions (L ≤ 14). The energy relaxation vs. time is investigated using the waiting time method [1]. We start from different initial states, one of them is a random high-energy state, the other one is a ground state. The approach of both curves is used as an indication for a lower bound of the relaxation time, which is needed to achieve the equilibrium. It is found that the same energy can be reached at all temperatures for small samples (L ≤ 6). Otherwise, for larger samples an energy gap Eg remains between both curves for low temperatures despite very long times of computer simulation. The dependence of Eg on temperature and its scaling with L is analyzed provided that the simulation times are equal for all samples. The freezing effects restraining the equilization are discussed. [1] J. Dall, P. Sibani, Comp. Phys. Commun. 141 (2001) 260