Low-Dimensional Quantum Magnets : Single Crystal Growth and Heat Transport Properties

Investigating heat transport in the solid state has always proved to be of fundamental and applied importance. Crucial information regarding generation, scattering and dissipation of excitations can be obtained from transport experiments. Recently, in various low-dimensional quantum magnets (arrangements of antiferromagnetically coupled S=1/2 spins in geometries of planes, ladders and chains) like the one-dimensional spin-chain compounds, Sr2CuO3 and SrCuO2, the two-dimensional Heisenberg antiferromagnet La2CuO4, and spin-ladder compounds like (Sr, Ca, La)14Cu24O41, huge thermal conductivities due to spin excitations have been observed [1-4]. This has enabled the investigation of the nature of dispersive spin excitations in these quantum magnets via systematic heat transport experiments. In this talk, we will discuss some recent thermal conductivity measurements on pure and doped versions of such single crystalline low-dimensional cuprates grown by the travelling-solvent floating zone method, with a view to understand relevant scattering mechanisms that are responsible for heat conduction in such materials.

[1] C. Hess, The European Physical Journal Special Topics 151, 73 (2007).
[2] C. Hess, et al., Phys. Rev. Lett. 90, 197002 (2003).
[3] A. V. Sologubenko, et al., Phys. Rev. B 62, R6108 (2000).
[4] C. Hess, et al., Phys. Rev. B 64, 184305 (2001).