Nuclear relaxation in the spin antiferromagnetic chain compound Comparison between theories and experiments

Abstract

The NMR relaxation data on (Formula presented) [Phys. Rev. Lett. 76, 4612 (1996)] are reexamined and compared with the analytic theory of the dynamic susceptibility in the (Formula presented) 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 ((Formula presented) and (Formula presented)) 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 (Formula presented) is well described by an (Formula presented) one-dimensional Heisenberg model with a nearest-neighbor exchange. © 1997 The American Physical Society.