Local magnetic impurities in the 2D quantum Heisenberg antiferromagnet
Abstract
We consider the two-dimensional (2D) quantum Heisenberg antiferromagnet at zero temperature with two types of locally frustrating perturbations - an isolated ferromagnetic bond (FMB) and a quantum impurity spin, coupled symmetrically to the two sublattices. An analytic technique is developed to study strong defect-environment interaction. In the case of a FMB we find that, contrary to the previous linear spin-wave result, the local magnetization stays finite even for strong frustration. For an antiferromagnetic coupling of a quantum impurity spin with its environment, we find a local ground state transition. All our calculations are compared with numerical results from exact diagonalization on small clusters.
Keywords
Cite
@article{arxiv.cond-mat/9712281,
title = {Local magnetic impurities in the 2D quantum Heisenberg antiferromagnet},
author = {V. N. Kotov and J. Oitmaa and O. Sushkov},
journal= {arXiv preprint arXiv:cond-mat/9712281},
year = {2009}
}
Comments
17 pages, REVTex, 5 Postscript figures