High-Frequency Waves and Landau Fermi-Liquid Effects in Noble Metals

Abstract

A theorem concerning the symmetry properties of the expansion coefficients of the Landau $f$ function for anisotropic systems is proved. We then calculate the dispersion curves of the ordinary high-frequency waves (HFW) in copper in the region of small wave number $\overrightarrow{\mathrm{q}}$, for the static field ${\overrightarrow{\mathrm{H}}}_0$ and current $\overrightarrow{\mathrm{j}}$ in the [100] direction ($\overrightarrow{\mathrm{q}}\perp {\overrightarrow{\mathrm{H}}}_0$), paying attention to the parts of the Fermi surface which touch the boundary of the Brillouin zone. We do this by reducing the transport equation to a system of linear equations, and by looking for a condition under which there exist normal-mode solutions to the system of equations. We carry out the calculation, first excluding and then including Landau Fermi-liquid effects. Qualitative differences are found between dispersion curves in alkali and noble metals.