arXiv:1007.3608 · Physical Review B
Dynamics of a Heisenberg spin chain in the quantum critical regime: NMR experiment versus effective field theory
H. Kühne, Andrei A. Zvyagin, M. Günther, Arneil P. Reyes, P. L. Kuhns, Mark M. Turnbull, C.P. Landee, H.‐H. Klauß
Abstract
A comprehensive comparison between the magnetic field- and temperature-dependent low-frequency spin dynamics in the antiferromagnetic spin-1/2 Heisenberg chain system copper pyrazine dinitrate, probed via the $^{13}\mathrm{C}$ nuclear magnetic resonance relaxation rate ${T}_{1}^{\ensuremath{-}1}$, and the field theoretical approach in the Luttinger liquid regime was performed. We found very good agreement between experiment and theory in the investigated temperature and field range. Our results demonstrate how spin-spin interactions strongly affect the spin dynamics of Heisenberg spin chain compounds in the vicinity of the quantum critical point.