2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90814Computer simulations of decoherence in quantum spin systems require the solution of the time-dependent Schrodinger equation for interacting quantum spin systems over extended periods of time. We use exact diagonalization, Chebyshev polynomial technique, four Suzuki-formula algorithms, and the short-iterative-Lanczos method to solve a simple model for decoherence of a quantum spin system by an environment consisting of quantum spins, and compare advantages and limitations of different algorithms.5 pages (llncs.sty, Springer style file), 1 EPS figure. The paper will appear in "Computer Simulation Studies in Condensed-Matter Physics XVI", eds. D.P. Landau et al., Springer Proceedings in Physics (Springer, Berlin, 2004)Quantum Physicstext