2003/12/31 by K. Kudo, M. Yamazaki, T. Kawamata +4
Physics and Astronomy · #cond-mat.str-el #cond-mat.stat-mech
paper · pdf · doi:10.1143/jpsj.73.2358
published as Journal of the Physical Society of Japan 73, 2358 (2004) · 4 pages, 4 figures
arxiv created 2004/09/16 · arxiv updated 2009/12/01
We have measured the thermal conductivity of a TlCuCl3 single crystal in magnetic fields up to 14 T. It has been found that the temperature dependence of the thermal conductivity exhibits a sharp peak at 4 K in zero field, which is suppressed by the application of magnetic fields up to 7 T. The peak is concluded to be attributable to the enhancement of the thermal conductivity due to phonons because of the formation of a spin-gap state. In high magnetic fields above 7 T, on the other hand, another sharp peak appears around 4 K and this is enhanced with increasing magnetic field. This peak is regarded as being attributable to the enhancement of the thermal conductivity due to magnons and/or phonons because of the drastic extension of the mean free path of magnons and/or phonons in the Bose-Einstein condensed state.