Magnetic density of states at low energy in geometrically frustrated systems.
Using muon-spin-relaxation measurements we show that the pyrochlore compound Gd(2)Ti(2)O(7), in its magnetically ordered phase below approximately 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.
Yaouanc
A
A
CEA/DSM/Département de Recherche Fondamentale sur la Matière Condensée, Grenoble, France.
de Réotier
P Dalmas
PD
Glazkov
V
V
Marin
C
C
Bonville
P
P
Hodges
J A
JA
Gubbens
P C M
PC
Sakarya
S
S
Baines
C
C