Investigation of two frustrated quantum magnets with a novel interaction scheme

The isostructural compounds ACuTe2O6 (A=Sr, Pb) consist of a 3-dimensional arrangement of spin-1/2 Cu ions. There are 3 potentially strong interactions, the first neighbor interaction couples the magnetic ions into isolated triangles, the second couples them into the highly frustrated hyperkagome lattice consisting of corner sharing triangles and the third neighbor interaction couples them into antiferromagnetic chains. In PbCuTe2O6 the hyperkagome interaction dominates suppressing long-range magnetic order completely, while in SrCuTe2O6 the chain interaction dominates while the other two interactions give rise to frustrated interchain coupling. We wish to explore the magnetic excitations of these two quantum magnets using inelastic neutron scattering on the LET spectrometer.