Staggered moment dependence on field-tuned quantum fluctuations in 2D frustrated antiferromagnets
Abstract
We propose an efficient method to identify the degree of frustration in quasi-2D antiferromagnets described by the J_1-J_2 Heisenberg model. The frustration ratio J_2/J_1 is usually obtained from analysis of susceptibility, specific heat and saturation field. We show that the non-monotonic field dependence of the staggered moment caused by the suppression of quantum fluctuations in a field depends strongly on the frustration ratio. This gives a powerful criterion to determine J_2/J_1 using a combination of exact diagonalization (ED) method for finite clusters and spin wave analysis. We apply this method to the quasi-2D compound Cu(pz)_2(ClO_4)_2 and show that it leads to an intermediate ratio J_2/J_1 ~ 0.2 for the frustration. We also explain the observed anomalous increase of transition temperature in applied fields as an effect of reduced quantum fluctuations.
Keywords
Cite
@article{arxiv.1108.1086,
title = {Staggered moment dependence on field-tuned quantum fluctuations in 2D frustrated antiferromagnets},
author = {Mohammad Siahatgar and Burkhard Schmidt and Peter Thalmeier},
journal= {arXiv preprint arXiv:1108.1086},
year = {2011}
}
Comments
5 pages, 5 figures, accepted for publication in Phys. Rev. B