Crystal-field and magnetic excitations in NdTa7O19

Rare-earth based geometrically frustrated magnets represent a promising new platform of searching for enigmatic quantum states of matter. Here, entanglement of spin and orbital degrees of freedom is believed to be one of the crucial factors that can stabilize disordered, yet highly quantum-entangled ground state. In our study, we focus on a novel rare-earth based triangular-lattice antiferromagnet NdTa7O19, where such effects might take place. Our previous measurement have demonstrated that magnetic order is absent in this material at least down to 66 mK. However, nothing is known about its low-lying excitations, which can be most conveniently revealed by inelastic neutron scattering. Such excitations may include those from crystal-field levels, the knowledge of which is essential for successful modelling of the magnetism in the investigated compound.