We report the first measurement of magnon thermal conductivity in monodomain single crystals of 3He in the U2D2 antiferromagnetic phase. The magnon mean free path λ was found first to rise rapidly upon cooling below TN and then more slowly at low temperatures, depending upon the sample. The temperature dependence is consistent with magnon umklapp scattering at high T, i.e., λ proportional to T-2 exp(Δ/kBT), with Δ/kB determined to be 5.8(±0.3) mK. The limiting low-temperature values of λ. varied from 0.3 to 3 μm. a Department of Physics, Cornell University, Ithaca, NY 14853.
ASJC Scopus subject areas
- Physics and Astronomy(all)