Layered He-4 and He-3-He-4 mixture between two surfaces - art. no. 134503

We examine the static, dynamic, and low-temperature thermodynamic propertie s of liquid He-4 and the low-concentration limit of He-3-He-4 mixtures conf ined between two walls. A generalized variational JastrowFeenberg ansatz wi th time-dependent correlations is used for describing the excited states; t he present variant accounts for up to three-phonon effects. We show that wi th decreasing wall separation the quantum liquid goes though a sequence of confined layering transitions familiar from classical fluids. These transit ions are due to the geometry and have potentially observable effects in the roton excitations near wave vector k similar to 2 Angstrom (-1). in high-d ensity liquid He-4, He-3 impurities assemble in the middle of the gap formi ng a nearly perfect two-dimensional Fermi-liquid layer.