For the weakly coupled S = 1 antiferromagnetic Heisenberg chains on a simple cubic lattice, the effects of magnetic impurities are investigated by the quantum Monte Carlo method with the continuous-time loop algorithm. The transition temperatures of the impurityinduced phase transitions for magnetic impurities with S = 1/2, 3/2, and 2 are determined and compared with the transition temperature induced by the non-magnetic impurities. Implications on the experimental results are discussed. §1. Impurity-Induced Phase Transitions There have been extensive studies on the phase transitions caused by magnetic fields and/or impurities in the low-dimensional quantum gapped magnets, which do not show phase transitions down to zero temperature. Among them, the nonmagnetic-impurity-induced phase transitions in the spin-Peierls material CuGeO3 1) and the Haldane material PbNi2V2O8 2) have been experimentally investigated and the temperature-dependence of the impurity-induced transition temperature has been determined. Recently in the experiment on PbNi2V2O8, the transition temperature induce
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.