Nanoscale molecular superfluidity of hydrogen

We present a microscopic quantum theoretical analysis of the nanoscale superfluid properties of solvating clusters of para-H-2 around the linear OCS molecule. Path-integral calculations with N=17 para-H-2 molecules, constituting a full solvation shell, show the appearance of a significant superfluid response to rotation around the molecular axis at T=0.15 K. This low-temperature superfluid response is highly anisotropic and drops sharply as the temperature increases to Tsimilar to0.3 K. These calculations provide definitive theoretical evidence that an anisotropic superfluid state exists for molecular hydrogen in this microscopic solvation layer.