The macroscopic theory of Fermi liquids we have developed in the preceding chapters possesses the advantage of being exact for any normal liquid, irrespective of its density or law of interaction, so long as the temperature is sufficiently low and the phenomena under discussion involve both long wavelengths and low frequencies. It is, of course, incomplete, since it can provide no account of microscopic phenomena involving short wavelengths and large excitation energies, or of equilibrium properties such as the ground state energy and pair distribution function. In contrast, microscopic theories are able to describe both macroscopic and microscopic phenomena. They are, however, subject to one of the following limitations: They are exact for only a limited range of particle density or interaction, one which rarely corresponds to physical reality. The extent to which they provide an approximate account of a real physical system can rarely be estimated with any precision.The macroscopic theory of Fermi liquids we have developed in the preceding chapters possesses the advantage of being exact for any normal liquid, irrespective of its density or law of interaction, so long as the temperature is sufficiently low and the phenomena under discussion involve both long wavelengths and low frequencies. It is, of course, incomplete, since it can provide no account of microscopic phenomena involving short wavelengths and large excitation energies, or of equilibrium properties such as the ground state energy and pair distribution function. In contrast, microscopic theories are able to describe both macroscopic and microscopic phenomena. They are, however, subject to one of the following limitations: They are exact for only a limited range of particle density or interaction, one which rarely corresponds to physical reality. The extent to which they provide an approximate account of a real physical system can rarely be estimated with any precision.

CRC Press eBooksMar 5, 20181 citation

Anomalous spin dynamics and relaxation in Fermi liquids

A. E. Meyerovich, Karen A. Musaelian

We explain the anomalous temperature dependence of spin diffusion in liquid $^{3}\mathrm{\ensuremath{\uparrow}}$ and $^{3}\mathrm{\ensuremath{-}}^{4}$He mixtures. The anomaly is an experimental manifestation of a unique zero-temperature attenuation in the Fermi liquid theory. We extended our microscopic theory of spin dynamics in spin-polarized Fermi liquids to finite temperatures. The zero-temperature attenuation changes the behavior of the spectrum near the singular point. The data indicate that the superfluid transition temperature for $^{3}\mathrm{He}$ in $^{3}\mathrm{\ensuremath{-}}^{4}$He mixtures is much lower than the current estimates.We explain the anomalous temperature dependence of spin diffusion in liquid $^{3}\mathrm{\ensuremath{\uparrow}}$ and $^{3}\mathrm{\ensuremath{-}}^{4}$He mixtures. The anomaly is an experimental manifestation of a unique zero-temperature attenuation in the Fermi liquid theory. We extended our microscopic theory of spin dynamics in spin-polarized Fermi liquids to finite temperatures. The zero-temperature attenuation changes the behavior of the spectrum near the singular point. The data indicate that the superfluid transition temperature for $^{3}\mathrm{He}$ in $^{3}\mathrm{\ensuremath{-}}^{4}$He mixtures is much lower than the current estimates.

Physical Review LettersMar 14, 199431 citations

Quasiparticle interactions in two-dimensional fluid He3 films adsorbed on graphite

C. P. Lusher, Brian P. Cowan, J. Saunders

The nuclear magnetic susceptibility of $^{3}\mathrm{He}$ adsorbed on the surface of graphite, plated with a monolayer of solid $^{4}\mathrm{He}$ , has been measured at surface densities less than 0.055 \AA{} $^{\mathrm{\ensuremath{-}}2}$ and at temperatures down to 6 mK. A temperature-independent susceptibility is observed at low temperatures, which is strongly enhanced over the ideal-gas value, due to quasiparticle interactions. The inferred Landau-Fermi-liquid parameters allow a comparison with microscopic theories of interacting Fermi systems.The nuclear magnetic susceptibility of $^{3}\mathrm{He}$ adsorbed on the surface of graphite, plated with a monolayer of solid $^{4}\mathrm{He}$, has been measured at surface densities less than 0.055 \AA{} $^{\mathrm{\ensuremath{-}}2}$ and at temperatures down to 6 mK. A temperature-independent susceptibility is observed at low temperatures, which is strongly enhanced over the ideal-gas value, due to quasiparticle interactions. The inferred Landau-Fermi-liquid parameters allow a comparison with microscopic theories of interacting Fermi systems.

Physical Review LettersOct 28, 199195 citations

^{3}\mathrm{He}

in $^{3}\mathrm{\ensuremath{-}}^{4}$He mixtures is much lower than the current estimates.

The nuclear magnetic susceptibility of

^{3}\mathrm{He}

adsorbed on the surface of graphite, plated with a monolayer of solid

^{4}\mathrm{He}

, has been measured at surface densities less than 0.055 \AA{} $^{\mathrm{\ensuremath{-}}2}$ and at temperatures down to 6 mK. A temperature-independent susceptibility is observed at low temperatures, which is strongly enhanced over the ideal-gas value, due to quasiparticle interactions. The inferred Landau-Fermi-liquid parameters allow a comparison with microscopic theories of interacting Fermi systems.