2011/12/31 by N. Hlubek, N Hlubek, X. Zotos +11 · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Chain (unit) #Cuprate #Exponential function #Mean free path #Physics of Superconductivity and Magnetism #Realization (probability) #Scattering #Spinon #Theoretical and Computational Physics #Thermal conductivity #cond-mat.str-el
paper · pdf · doi:10.1088/1742-5468/2012/03/p03006
published as J. Stat. Mech. (2012) P03006 · revised version, accepted by: Journal of Statistical Mechanics: theory and experiment
arxiv created 2012/02/17 · openalex publication_date 2012/03/12 · arxiv updated 2012/03/21 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have investigated the thermal conductivity κ mag of high-purity single crystals of the spin chain compound Sr 2 CuO 3 , which is considered an excellent realization of the one-dimensional spin-1/2 antiferromagnetic Heisenberg model. We find that the spinon heat conductivity κ mag is strongly enhanced as compared to previous results obtained on samples with lower chemical purity. The analysis of κ mag allows the computation of the spinon mean free path l mag as a function of temperature. At low temperature we find l mag ∼ 0.5 µm, corresponding to more than 1200 chain unit cells. Upon increasing the temperature, the mean free path decreases strongly and approaches an exponential decay ∼ (1/ T )exp( T u * / T ), which is characteristic for Umklapp processes with the energy scale k B T u * . Based on Matthiessen's rule we decompose l mag into a temperature-independent spinon–defect scattering length l 0 and a temperature-dependent spinon–phonon scattering length l sp ( T ). By comparing l mag ( T ) of Sr 2 CuO 3 with that of SrCuO 2 , we show that the spin–phonon interaction, as expressed by l sp , is practically the same in both systems. The comparison of the empirically derived l sp with model calculations for the spin–phonon interaction of the one-dimensional spin-1/2 XY model yields reasonable agreement with the experimental data.