title: Susceptibility of the 2D spin-1 / 2 Heisenberg antiferromagnet with an impurity.
abstract: We use a quantum Monte Carlo method (stochastic series expansion) to study the effects of a magnetic or nonmagnetic impurity on the magnetic susceptibility of the two-dimensional Heisenberg antiferromagnet. At low temperatures, we find a log-divergent contribution to the transverse susceptibility. We also introduce an effective few-spin model that can quantitatively capture the differences between magnetic and nonmagnetic impurities at high and intermediate temperatures.
authors.affiliation: Department of Physics, Abo Akademi University, Porthansgatan 3, FIN-20500 Turku, Finland.
authors.forename: Kaj H
authors.initials: KH
authors.lastname: Höglund
authors.forename: Anders W
authors.initials: AW
authors.lastname: Sandvik