Microscopic origins of superfluidity in confined geometries

An analysis of the excitation spectrum of superfluid helium confined in porous aerogel glass explains the microscopic origin of the macroscopic fluid behavior. Neutron inelastic scattering estimations of the spectrum show that the elementary excitations, rotons, influence the system's behavior near the superfluid transition temperature. The effective mass of the rotons increases and their lifetime decreases in the system as compared to an unconfined disordered system. There are no theoretical explanations regarding the changes in the system.