Field-dependent thermal transport in the haldane chain compound NENP.
We present a study of the magnetic field-dependent thermal transport in the spin S=1 chain material Ni(C(2)H(8)N(2))(2)NO(2)(ClO(4)) (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.
II. Physikalisches Institut, Universität zu Köln, 50937 Köln, Germany.
A V
AV
Sologubenko
T
T
Lorenz
J A
JA
Mydosh
A
A
Rosch
K C
KC
Shortsleeves
M M
MM
Turnbull