Spin diffusion in a degenerate Fermi liquid is studied, taking into account the effects of the 'molecular field' resulting from the interactions between quasiparticles. It is shown that even in the hydrodynamic limit no diffusion equation of the conventional form exists in general; the true equation is nonlinear and depends on the strength of the interactions. Substantial new effects are therefore predicted when lambda Omega//0tauD is more than a number of 1, where Omega//0 is the Larmor frequency, tauD the spin diffusion lifetime and lambda a dimensionless parameter which measuresthe strength of the molecular field. Specifically, it is predicted that the spin-echo attenuation in a 'phi- 180- 180' experiment will in general not be exponential and will depend on the external field and the initial pulse angle phi. The new effects should lie in the experimentally accessible region both for pure He- 3 and for mixtures.
|Title of host publication||J Phys C (Solid State Phys)|
|Number of pages||12|
|State||Published - Feb 1 1970|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics