The nature of spin correlations in the novel triangular lattice antiferromagnet ErTa7O19

Rare-earth (RE) based geometrically frustrated magnets represent a promising avenue in the search of enigmatic quantum spin liquids (QSLs). Our previous study has identified a novel family of RE heptatantalates RETa7O19, where in the Nd case strong Ising anisotropy on the triangular lattice leads to a QSL state. As the nature of the RE ions can strongly influence the magnetic anisotropy we initiated a study of isostructural ErTa7O19 with twice stronger magnetic interactions. Recent neutron diffraction measurements done on the WISH instrument revealed sizable magnetic diffuse scattering as a signature of short-range spin correlations. Here we propose a high-resolution inelastic neutron scattering study on the LET instrument to determine whether the spin correlations are static or dynamical.