Europhys. Lett.
Volume 70, Number 2, April 2005
Page(s) 155 - 161
Section General
Published online 18 March 2005
Europhys. Lett., 70 (2), pp. 155-161 (2005)
DOI: 10.1209/epl/i2004-10486-8

ParQ -high-precision calculation of the density of states

F. Heilmann and K. H. Hoffmann

Institut für Physik, Technische Universität Chemnitz - D-09107 Chemnitz, Germany

received 22 October 2004; accepted in final form 2 March 2005
published online 18 March 2005

We present a highly effective, parallelized random-walk-based algorithm to calculate the density of states of complex physical systems. Random walkers' attempted moves from one energy level to another are represented in a stochastic matrix, giving estimates for the transition matrix at infinite temperature. The eigenvector corresponding to the largest eigenvalue is the density of states up to a normalization. We verify the performance on selected examples of Ising spin systems with random coupling constants drawn uniformly from [-1,1], of which the exact density of states has been calculated by a branch-and-bound approach.

02.50.Ga - Markov processes.
05.10.Ln - Monte Carlo methods.
05.50.+q - Lattice theory and statistics (Ising, Potts, etc.).

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