engleski

Heat conduction in spin-gap antiferromagnets

Heat conduction is a tool that probes the spin excitations and spin-phonon interaction in the spin-gap systems (antiferomagnets). A variety of phenomena are observed: for example, in various strontium-cuprates heat conduction is strongly enhanced due to the opening of the heat channel carried by either magnons or spinons ; in spin-Peierls compounds the heat transport exhibits rather unusual double peak at low temperatures, explained as a fingerprint of the spin-phonon resonance scattering. The heat conduction of strongly frustrated systems also shows the existence of spin-phonon resonance at low temperatures. We present the study of the heat transport of several spin-gap antiferomagnets: (i) copper-tellurides, quasi-1D geomatrically frustrated compounds with S=1/2, (b) a "zig-zag"frustrated spin ladder system LiCu2O2 (S=1/2), and (c) quasi-2D S=1 system nickel-telluride. We find that the heat conduction of these systems exhibit behaviour typical for spin-phonon resonance coupling, and it gradually decreases as the dimensionality of the systems increase.

spin-gap antiferomagnets; copper-tellurides; spin ladder system LiCu2O2; nickel-tellurides; heat conduction

The paper was presented by Igor Smiljanić.