arXiv:cond-mat/9706177 · Physical review. B, Condensed matter
Nuclear relaxation in the spin- 1/2 antiferromagnetic chain compound Sr2CuO3: Comparison between theories and experiments
Masashi Takigawa, Oleg A. Starykh, Anders W. Sandvik, Rajiv R. P. Singh
Abstract
The NMR relaxation data on ${\mathrm{Sr}}_{2}{\mathrm{CuO}}_{3}$ [Phys. Rev. Lett. 76, 4612 (1996)] are reexamined and compared with the analytic theory of the dynamic susceptibility in the $S=1/2$ antiferromagnetic Heisenberg chain including multiplicative logarithmic corrections [Phys. Rev. Lett. 78, 539 (1997)]. Comparisons of the spin-lattice and the Gaussian spin-echo decay rates (${1/T}_{1}$ and ${1/T}_{2G}$) and their ratio all show good quantitative agreement. Our results demonstrate the importance of the logarithmic corrections in the analysis of experimental data for quasi-one-dimensional systems and indicate that the dynamics of ${\mathrm{Sr}}_{2}{\mathrm{CuO}}_{3}$ is well described by an $S=1/2$ one-dimensional Heisenberg model with a nearest-neighbor exchange.