Spin anisotropy of Seff=1/2 triangular rare-earth based antiferromagnets

In quantum magnetism significant efforts have been devoted to the search for new quantum states. In particular the Quantum Spin Liquid (QSL) state on the triangular lattice has attracted a lot of attention as it shows intriguing collective phenomena such as fractionalized excitations. We have synthesized a large amount (5g) of polycrystalline samples of four members of the Ba6R2Ti4O17 (BaRTiO) Seff=1/2 triangular antiferromagnets family, with R = Yb, Nd, Er and Y. Here, we propose to use neutron spectroscopy to determine the spin anisotropy of the effective S=1/2 triangular antiferromagnets of this family. The single-ion anisotropy is a crucial parameter to determine in order to confront the observed ground states to the theoretical phase diagram of the anisotropic triangular model, where QSL states have been predicted.