Quantum Monte Carlo study of the Hubbard model doped with nonmagnetic impurities

摘要

We calculate the net magnetization for the a dimensional half-filled Hubbard model doped with one and multiple nonmagnetic impurities, using quantum Monte Carlo (QMC) method, to understand the suppression of antiferromagnetic order in strongly correlated electron systems such as La2CuO4 by doping nonmagnetic impurities, e.g. Zn. The QMC results show enhancement of magnetic correlations around an impurity, in agreement with the results obtained in previous Studies. The effect of all impurity oil the magnetic structure around it and the underlying mechanism is discussed. The Situation with additional doping with holes is also examined by carrying out QMC simulation of the Hubbard model at band filling slightly less than half-filling. (c) 2006 Elsevier B.V. All rights reserved.