Physical review. B, Condensed matter
Susceptibility behavior of CuGeO3: Comparison between experiment and the quantum transfer-matrix approach
G. Kamieniarz, M. Bieliński, Jean‐Pierre Renard
Abstract
Thermodynamical properties of the one-dimensional $S=1/2$ Heisenberg model with dimerized nearest and uniform next-nearest neighbor interactions are studied by the numerically exact quantum transfer-matrix method and the results are applied to ${\mathrm{CuGeO}}_{3}.$ The Suzuki-Trotter formula is used to obtain a classical system with spin $\ensuremath{\sigma}=3/2$ and effective interactions between nearest neighbors only. The magnetic susceptibility curve is calculated and compared with experimental results in a wide temperature range, revealing the presence of frustration in the model proposed for ${\mathrm{CuGeO}}_{3}.$ Temperature dependence of the dimerization parameter below the spin-Peierls transition point is also estimated.