We study a novel S=1/2 cluster chain Hamiltonian which has recently been proposed in the context of the charge ordered low-temperature phase of alpha'-NaV2O5. We perform a detailed investigation of this model within a large range of parameters using perturbation theory and Lanczos diagonalization. Using model-specific local conservation laws and parameter-dependent mappings to various effective low-energy Hamiltonians we uncover a rich phase diagram and several regimes of gapful spin-excitations. We find that the overall features of recent neutron scattering data on alpha'-NaV2O5 can be fitted within this model, however using a set of parameters which seems unlikely.
@article{arxiv.cond-mat/0009298,
title = {Magnetic properties of a spin-1/2 quadrumer chain},
author = {Andreas Honecker and Wolfram Brenig},
journal= {arXiv preprint arXiv:cond-mat/0009298},
year = {2009}
}
Comments
9 pages REVTeX, 11 PostScript figures included using psfig.sty; final version to appear in Phys. Rev. B: New appendix, modified Figs. 1 & 10 and other small changes