2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/227451We study the ground-state phase transitions of quasi-one-dimensional quantum Heisenberg antiferromagnets by the quantum Monte Carlo method with the continuous-time loop algorithm and finite-size scaling. For a model which consists of S=1 chains with bond alternation coupled on a square lattice, we determine the ground state phase diagram and the universality class of the quantum phase transitions.5 pages, 3 figures, proceedings for the 16th Annual Workshop "Recent Developments in Computer Simulation Studies in Condensed Matter Physics", Center for Simulational Physics, University of Georgia, USA, 2003Strongly Correlated Electronstext