2000/04/14 by Christian Knetter, Götz S. Uhrig, Goetz S. Uhrig
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Electronic and Structural Properties of Oxides #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.63.094401
published as Phys. Rev. B 63, 94401 (2001) · 8 pages, 10 figures, submitted to Phys. Rev. B
arxiv created 2000/04/14 · openalex publication_date 2001/01/25 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We reconsider the two-dimensional model for CuGeO3 introduced previously [Phys. Rev. Lett. 79, 163 (1997)]. Using a computer aided perturbation method based on flow equations we expand the 1-triplet dispersion up to 10th order. The expansion is provided as a polynom in the model parameters. The latter are fixed by fitting the theoretical result to experimental data obtained by inelastic neutron scattering. For a dimerization \ensuremathδ\ensuremath≈0.08(1) we find an excellent agreement with experiment. This value is at least 2 to 3 times higher than values deduced previously from one-dimensional chain approaches. For the intrachain frustration \ensuremathα0 we find a smaller value of 0.25(3). The existence of interchain frustration conjectured previously is confirmed by the analysis of temperature-dependent susceptibility.