We present a study of the magnetic field-dependent thermal transport in the spin S=1 chain material Ni(C2H8N2)2NO2(ClO4) (NENP). The measured thermal conductivity is found to be very sensitive to the field-induced changes in the spin excitation spectrum. The magnetic contribution to the total heat conductivity is analyzed in terms of a quasiparticle model, and we obtain a temperature and momentum independent mean free path. This implies that the motion of quasiparticles is effectively three dimensional despite the tiny interchain coupling.
@article{arxiv.0712.3991,
title = {Field-dependent thermal transport in the Haldane chain compound NENP},
author = {A. V. Sologubenko and T. Lorenz and J. A. Mydosh and A. Rosch and K. C. Shortsleeves and M. M. Turnbull},
journal= {arXiv preprint arXiv:0712.3991},
year = {2008}
}