Temperature and pressure dependence of viscosity of quantum liquid 4 He according to significant structure theory

Abstract

Both solid-like and gas-like flow structures are considered in the calculation of viscosity of liquid (4)He using the significant structure theory of liquids. The predominance of quantum mechanical zero-point motion over that arising from thermal excitation is taken into account for the solid-like motion of molecules. The viscosity of liquid (4)He under its own vapor pressure calculated over its whole temperature range is in reasonably good agreement with experimental data. The pressure dependence of viscosity also was obtained. The calculation does not yield good results at high densities where the free jumping of molecules into the nearest neighboring vacancies through the kinetic zero-point motion is no longer plausible.