17O NMR study of q = 0 spin excitations in a nearly ideal S = 1 / 2 1D Heisenberg antiferromagnet, Sr2CuO3, up to 800 K

K R Thurber; A W Hunt; T Imai; F C Chou

doi:10.1103/PhysRevLett.87.247202

17O NMR study of q = 0 spin excitations in a nearly ideal S = 1 / 2 1D Heisenberg antiferromagnet, Sr2CuO3, up to 800 K

Phys Rev Lett. 2001 Dec 10;87(24):247202. doi: 10.1103/PhysRevLett.87.247202. Epub 2001 Nov 26.

Authors

K R Thurber¹, A W Hunt, T Imai, F C Chou

Affiliation

¹ Department of Physics, MIT, Cambridge, Massachusetts 02139 and Center for Materials Science and Engineering, MIT, Cambridge, Massachusetts 02139.

PMID: 11736538
DOI: 10.1103/PhysRevLett.87.247202

Abstract

We used 17O NMR to probe the uniform (wave vector q = 0) electron spin excitations up to 800 K in Sr2CuO3 and separate the q = 0 from the q = +/-pi / a staggered components. Our results support the logarithmic decrease of the uniform spin susceptibility below T approximately 0.015J, where J = 2200 K. From measurement of the dynamical spin susceptibility for q = 0 by the spin-lattice relaxation rate 1/T(1), we demonstrate that the q = 0 mode of spin transport is ballistic at the T = 0 limit, but has a diffusion-like contribution at finite temperatures even for T<<J.