title: Thermodynamics of the bilinear-biquadratic spin-One heisenberg chain
abstract: The magnetic susceptibility and specific heat of the one-dimensional S = 1 bilinear-biquadratic Heisenberg model are calculated using the transfer matrix renormalization group. By comparing the results with the experimental data of LiVGe2O6 measured by Millet et al. [Phys. Rev. Lett. 83, 4176 (1999)], we find that the susceptibility data of this material, after subtracting the impurity contribution, can be quantitatively explained with this model. The biquadratic exchange interaction in this material is found to be ferromagnetic, i.e., with a positive coupling constant.
authors.affiliation: Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100080, People's Republic of China.
authors.initials: J
authors.lastname: Lou
authors.initials: T
authors.lastname: Xiang
authors.initials: Z
authors.lastname: Su