Investigating the ground state of the proposed valence bond glass Ba2LuMoO6

Geometrically frustrated magnetic systems have been widely studied in the search for novel quantum states of matter. The fcc lattice Ba2YMoO6 has been shown to be a valence bond glass, where the magnetic 4d1 Mo5+ electrons form non-magnetic singlets in a random distribution. We have prepared the isostructural Ba2LuMoO6 compound, which behaves similarly in magnetic susceptibility measurements. In our previous muSR experiment we showed that this compound does not order magnetically down to 1.5 K. However, this temperature was not low enough to establish the ground state, as significant changes in relaxation are observed between 1.5 and 3.5 K. We propose a dilution fridge experiment on MUSR down to 50 mK to conclusively determine the ground state of Ba2LuMoO6. MuSR will allow us to observe whether the material is a valence bond glass or if a magnetic transition/spin freezing occurs.