Atomic-scale quantum solvation structure in superfluid helium-4 clusters

The local superfluid density around a molecule embedded in a He-4(N) cluster at low temperatures is analyzed using the path-integral Monte Carlo method. The molecular interaction induces a local nonsuperfluid component within a quantum solvation shell whose size is determined by the range of the molecule-helium interaction, and also introduces an anisotropic layering of the superfluid density around the molecule. We show that a local quantum hydrodynamic analysis is internally consistent for N > 50, and can be used to calculate effective rotational constants for molecular dopants in superfluid helium.