Berlin 2015 – wissenschaftliches Programm
TT 71.31: Poster
Mittwoch, 18. März 2015, 15:00–18:00, Poster B
High-temperature heat transport in spin-1/2 quantum magnets — •Christian Hess1,2, Oleg Mityashkin1, Ashwin Mohan1, Chinnathambi Sekar1, Gernot Krabbes1, Sabine Wurmehl1, Bernd Büchner1,2, Romuald Saint-Martin3, and Alexandre Revcolevschi3 — 1Institute for Solid State Research, IFW Dresden, 01069 Dresden, Germany — 2Center for Transport and Devices, Technische Universität Dresden, 01069 Dresden, Germany — 3Laboratoire de Physico-Chimie de L’Etat Solide, Université Paris-Sud, 91405 Orsay, France
Some years ago, a new, magnetic mode of heat transport has been discovered in low-dimensional spin-1/2 quantum magnets, i.e. spin planes, spin-ladders, and chains as realized in cuprate materials with large magnetic exchange J/kB∼2000 K, and is intensely studied since then. The magnetic heat conductivity of such quantum magnet materials can be exceptionally large (even at room temperature), dwarfs the phonon heat conduction and thereby leads to an overall magnitude of the heat conductivity which can be comparable to that of metals. Here we present recent results which extend the accessible temperature range towards high temperature, approaching, for the first time, kBT≈ J/2. The data provide fresh experimental input that allows to rationalize the high-temperature scattering processes for elementary excitations of the quantum magnets.