Finite temperature effects in the Fermi liquid theory of the diffusion of ⁴He in ³He

• Main Authors: Hjort, H.H., Culman, T.G., Edwards, D.O., Jizhong He
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 1997
• Series: Физика низких температур
• Subjects: Квантовые жидкости и квантовые кpисталлы
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/175465

The diffusion coefficient D and the thermal diffusion ratio kT for dilute ⁴He in liquid ³He are calculated from Fermi liquid theory. The collision integral assumes a scattering amplitude a³⁴ expanded in scalar combinations of the quasiparticle momenta. As T→0, D varies as 1/T and kT/c, where c is the concentration, approaches a constant. As shown previously, the limits for DT and kT/c are determined by thermodynamic properties, the ⁴He effective mass and partial volume, and properties of pure ³He. We have decreased kT/c by a few percent, by including the effect of ∇T on the ³He distribution function. The temperature dependence of DT and kT/c is linear and related to the coefficients in the expansion of a³⁴. Two coefficients can be found from thermodynamics. A conjecture about the remainder suggests that DT may have a maximum between 0 and 0.5 K.