Abstract
The approximate form of the effective interaction between atoms in superfluid is derived from the experimental data on spin diffusion and phase seperation in dilute mixtures of in . The interaction is weak, and attractive at long wavelengths. Calculations of the Fermi-liquid parameters for the normal state of in solution yield results for the effective mass and spin susceptibility in agreement with experiment. The temperature for a superfluid transition associated with the is estimated to be ∼2× °K; the maximum solubility of in is found to be ∼6% at . Thermodynamic and microscopic arguments are used to calculate the long-wavelength part of the effective interaction between the atoms. The contribution arising from the exchange of a virtual phonon is shown to be large and attractive, while the remaining part of the interaction is almost as large but repulsive; the calculated interaction at long wavelengths is thus weak and attractive and is in excellent agreement with that determined empirically; the physical origin of the weakness of the interaction is that is an isotopic impurity. Finally, it is estimated that the application of pressure serves to weaken the effective interaction.
- Received 10 November 1966
DOI:https://doi.org/10.1103/PhysRev.156.207
©1967 American Physical Society