Quantum vs. Geometric Disorder in a Two-Dimensional Heisenberg Antiferromagnet
Disordered Systems and Neural Networks
2009-11-07 v4 Strongly Correlated Electrons
Abstract
We present a numerical study of the spin-1/2 bilayer Heisenberg antiferromagnet with random interlayer dimer dilution. From the temperature dependence of the uniform susceptibility and a scaling analysis of the spin correlation length we deduce the ground state phase diagram as a function of nonmagnetic impurity concentration p and bilayer coupling g. At the site percolation threshold, there exists a multicritical point at small but nonzero bilayer coupling g_m = 0.15(3). The magnetic properties of the single-layer material La_2Cu_{1-p}(Zn,Mg)_pO_4 near the percolation threshold appear to be controlled by the proximity to this new quantum critical point.
Keywords
Cite
@article{arxiv.cond-mat/0206356,
title = {Quantum vs. Geometric Disorder in a Two-Dimensional Heisenberg Antiferromagnet},
author = {O. P. Vajk and M. Greven},
journal= {arXiv preprint arXiv:cond-mat/0206356},
year = {2009}
}
Comments
minor changes, updated figures