Thermal Conductivity due to Spinons in the One-Dimensional Quantum Spin   System Sr2V3O9
  We have measured the thermal conductivity along different directions of the S = 1/2 one-dimensional (1D) spin system Sr2V3O9 in magnetic fields up to 14 T. It has been found that the thermal conductivity along the [10-1] direction, \k{appa}[10-1], is large and markedly suppressed by the application of magnetic field, indicating that there is a large contribution of spinons to \k{appa}[10-1] and that the spin chains run along the [10-1] direction. The maximum value of the thermal conductivity due to spinons is ~14 W/Km along the [10-1] direction, supporting the empirical law that the magnitude of the thermal conductivity due to spinons is roughly proportional to the antiferromagnetic interaction between the nearest neighboring spins. 
Takayuki Kawamata, Masanori Uesaka, Mitsuhide Sato, Koki Naruse,   Kazutaka Kudo, Norio Kobayashi, and Yoji Koike
cond-mat.str-el