Thin Films of Quantum Fluids: History, Phase Transitions, and Wetting

Thin films of quantum fluids, i.e., He, He, and H, have played an important role in understanding the phenomenology of quantum fluids and the role of spatial dimension on the development of long-range order in condensed matter. Standard experimental probes used to study these systems include heat capacity measurements, torsional oscillators, third sound, quartz crystal microbalances, and x-ray and neutron scattering. We describe the historical development of important models and experiments in quantum films which underpin our understanding of superfluid onset in helium, phases, and phase transitions in adsorbed films, and wetting and growth of bulk phases.