Spin and Energy Transport in Anisotropic Magnetic Chains withS=12

Abstract

Spin and energy transport in spin-½ anisotropic magnetic chains with nearest-neighbor interactions are studied in the high-temperature limit. The analysis is based on a calculation of the zeroth, second, and fourth moments of the Fourier transforms of the spin and energy density correlation functions. Spin diffusion is predicted for sufficiently small values of the wave vector, except in the $\mathrm{XY}$ limit. Energy transport is nondiffusive for all values of the wave vector. Energy diffusion is predicted for chains with isotropic nearest-neighbor interactions and spin greater than ½ as well as for spin-½ two-dimensional square lattices and three-dimensional simple and body-centered cubic lattices having isotropic nearest-neighbor interactions.