NMR investigation of the quantum spin liquid candidate Na₃Sc₂(MoO₄)₂Mo₃O₈

In recent years, we have witnessed a growing interest in quantum spin liquids (QSLs) for their unconventional fractional excitations such as spinons and Majorana fermions and for possible applications in quantum computing. While the origin of likely QSL states in systems with a standard kagome lattice is fairly evident, a number of molybdate materials with a more complicated model have also recently been shown to be strong QSL candidates [1]. Here we present our NMR results on the [Mo₃]¹¹⁺-based molecular magnet, Na₃Sc₂(MoO₄)₂Mo₃O₈. This spin-1/2 Heisenberg kagome system shows no long-range ordering or spin freezing down to 20mK according to µSR measurements [1], pointing towards a dynamical QSL ground state. Here, we present ²³Na Knight shift and spin-lattice relaxation rate measurements that allow us to measure this material’s intrinsic, local susceptibility and probe the spin fluctuations induced by exotic gapless spin excitations.

[1] Chen, Q. et al. Magnetic order and spin liquid behavior in [Mo₃]¹¹⁺ molecular magnets. Phys. Rev. Materials 6, 044414 (2022).