Magnetic density of states at low energy in geometrically frustrated systems

Yaouanc, A.; de Reotier, P. Dalmas; Glazkov, V.; Marin, C.; Bonville, P.; Hodges, J. A.; Gubbens, P. C. M.; Sakarya, S.; Baines, C.

Magnetic density of states at low energy in geometrically frustrated systems

Authors

Yaouanc, A.

de Reotier, P. Dalmas

Description

Using muon-spin-relaxation measurements we show that the pyrochlore compound Gd2Ti2O7, in its magnetically orderered phase below ~ 1 K, displays persistent spin dynamics down to temperatures as low as 20 mK. The characteristics of the induced muon relaxation can be accounted for by a scattering process involving two magnetic excitations, with a density of states characterized by an upturn at low energy and a small gap depending linearly on the temperature. We propose that such a density of states is a generic feature of geometrically frustrated magnetic materials.
5 pages, two figures