Physical Review B
Thermal conductivity of one-dimensional spin- 1∕2 systems coupled to phonons
Kim Louis, Peter Prelovšek, X. Zotos
Abstract
Within the memory function approach we study the thermal conductivity of the one-dimensional spin-$1∕2$ Heisenberg, as well as $XY$ model coupled to optic and acoustic phonons using exact diagonalization with the Lanczos technique and analytical evaluation, respectively. We find that the thermal conductivity of the two models is fairly similar, the enhancement found in the Heisenberg model mainly due to the larger energy current correlations. We also observe that the Wiedemann-Franz law is not obeyed in the $XY$ model, presumably due to the inelastic scattering processes.