Cu3LiRu2O6: a 4d4 (Jeff = 1) based possible Quantum Spin Liquid

Honeycomb lattices are a fertile playground for exploring Kitaev physics. The interplane spacing can be tuned by changing the spacer atom (H, Ag, or Cu in our case). This impacts the magnetic in-plane interactions. Also, the magnetic atoms in the honeycomb plane can be changed (Ir, Ru or a mixture of the two) to tailor the magnetism of the system. The phase diagram is rich: ranging from the usual ordered state to the Kitaev Spin Liquid state with dynamic moments. In the given proposal, muSR will be carried out to probe the nature of the ground state in Cu3LiRu2O6 which shows no sign of long-range order down to 400 mK whereas a non-zero spin susceptibility is inferred from the 7Li NMR shift data. It appears that the Ru4+ is stabilised in a magnetic state rather than the expected J = 0 state. The formation of the novel excitonic spin liquid might be suggested in this case. Muon depolarisation rate and its temperature dependence, effect of longitudinal field on the decoupling will be examined.