Fermi liquid properties of ³He –⁴He mixtures

• Main Authors: Scho, K., Krotscheck, E., Paaso, J., Saarela, M., Zillich, R.
• Language: English
• Published: Інститут фізики конденсованих систем НАН України 1999
• Series: Condensed Matter Physics
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/120386

We calculate microscopically the properties of ³He impurity atoms in ³He-⁴He mixtures, including the spectrum of a single particle and the Fermi–Liquid interaction between ³He atoms. From these, we determine the pressure and concentration dependence of the effective mass and the magnetic susceptibility. The long wavelength limit of the single–particle spectrum defines the hydrodynamic effective mass. When k >= 1.7A⁻¹ the motion of the impurity is damped due to the decay into a roton and a low energy impurity mode. The calculations of the Fermi–Liquid interaction are based on correlated basis functions (CBF) perturbation theory; the relevant matrix elements are determined by the Fermi hypernetted–chain summation method. Our theoretical effective masses agree well with recent measurements [1,2] but our analysis suggests a new extrapolation to the zero-concentration limit. With that effective mass we also find a good agreement with the measured [3] Landau parameter F a ₀