Evidence of superfluidity in a dipolar supersolid from nonclassical rotational inertia

A key manifestation of superfluidity in liquids and gases is a reduction the moment inertia under slow rotations. Non-classical rotational effects have been searched for long time also elusive supersolid phase matter, which coexists with lattice structure. Here we show that recently discovered dipolar quantum features reduced inertia. We study peculiar oscillation mode harmonic potential, scissors mode, already employed superfluids. From measured inertia, infer superfluid fraction different from zero order unity, providing direct evidence nature supersolid.