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Replica-Exchange Algorithm And Results For The Three-Dimensional Random Field Ising Model, Jonathan Machta, M.E.J. Newman, L. B. Chayes
Replica-Exchange Algorithm And Results For The Three-Dimensional Random Field Ising Model, Jonathan Machta, M.E.J. Newman, L. B. Chayes
Jonathan Machta
The random field Ising model with Gaussian disorder is studied using a different Monte Carlo algorithm. The algorithm combines the advantages of the replica-exchange method and the two-replica cluster method and is much more efficient than the Metropolis algorithm for some disorder realizations. Three-dimensional systems of size 243 are studied. Each realization of disorder is simulated at a value of temperature and uniform field that is adjusted to the phase-transition region for that disorder realization. Energy and magnetization distributions show large variations from one realization of disorder to another. For some realizations of disorder there are three well separated peaks …
Cluster Monte Carlo Study Of Multicomponent Fluids Of The Stillinger-Helfand And Widom-Rowlinson Type, Rongfeng Sun, Harvey Gould, Jonathan Machta, L. W. Chayes
Cluster Monte Carlo Study Of Multicomponent Fluids Of The Stillinger-Helfand And Widom-Rowlinson Type, Rongfeng Sun, Harvey Gould, Jonathan Machta, L. W. Chayes
Jonathan Machta
Phase transitions of fluid mixtures of the type introduced by Stillinger and Helfand are studied using a continuum version of the invaded cluster algorithm. Particles of the same species do not interact, but particles of different types interact with each other via a repulsive potential. Examples of interactions include the Gaussian molecule potential and a repulsive step potential. Accurate values of the critical density, fugacity, and magnetic exponent are found in two and three dimensions for the two-species model. The effect of varying the number of species and of introducing quenched impurities is also investigated. In all the cases studied, …