Quantum spin liquid in the triangular antiferromagnet NdTa7O19

A spin-liquid state was predicted for Ising triangular antiferromagnet already in 1950, but never confirmed experimentally. Several complementary experiments that we have undertaken on a novel triangular antiferromagnet NdTa7O19 suggest that it might be the first to realize this enigmatic state. Our previous INS study (RB 1920405) has revealed that its crystal-electric-field ground-state Kramers’ doublet is characterized by highly anisotropic Ising exchange interactions between effective spin-1/2 degrees of freedom, while our muSR study (RB 1910518), suggests a quantum-disordered ground state with low-frequency excitations that are found to persist down to at least 66 mK. This work was submitted to Nature Materials, where one of the Reviewers demands additional confirmation by a neutron diffraction at millikelvin temperatures. We therefore ask for rapid access to the WISH instrument.