Surface Structure of Liquid Helium 4

Neutron reflection from the liquid helium surface

Charges near the free surface of liquid helium: collective effects

Two types of two-dimensional (2D) charged systems can appear near the free surface of liquid helium: surface electrons and surface ions [1]. The existence of these two systems has been predicted almost simultaneously (see Ref. [2] ). However, the electron variant of the problem has subsequently been investigated more thoroughly both theoretically and experimentally. The interest in 2D ion syste...

Calculation of the Condensate Fraction in Liquid Helium-4

We adduce the results of the condensate fraction calculation for liquid helium-4. The method is derived from the first principles and involves minimum assumptions. The only experimental quantity we need in our calculations is the static structure factor which is easily measurable. We use the approximation in which expressions contain one summation in the wave vector space (or one integration it...

Surface State Electron Dynamics on Deformed Liquid Helium Films

Electrons can form stable two-dimensional systems above the surface of dielectric substances like superžuid liquid helium (LHe). Due to the extreme purity and smoothness of the LHe surface, electrons on bulk LHe proved to be a versatile (with respect to the facility for changing physical parameters like temperature and magnetic eld, but especially electron density) and clean (with respect to e...

Microscopic surface structure of liquid alkali metals

We report an x-ray scattering study of the microscopic structure of the surface of a liquid alkali metal. The bulk liquid structure factor of the eutectic K67Na33 alloy is characteristic of an ideal mixture, and so shares the properties of an elemental liquid alkali metal. Analysis of off-specular diffuse scattering and specular x-ray reflectivity shows that the surface roughness of the K-Na al...