Электронные эффекты в динамической структуре жидких металлов

Abstract

The partial dynamical structure factors of a pure liquid metal are derived from the two-component theory developed in an earlier paper by March and Tosi. In particular, and in contrast to the usual procedure which assumes the hydrodynamic form for the ion-ion dynamical structureSii(q, ω) to be the same as for a classical one-component liquid, in the present theory the contribution to the sound-wave attenuation from single-particle excitations in the conduction electron system is derived explicitly. It is suggested that this is closely related to the anomalous scaling with isotopic mass of the atomic transport coefficients in liquid lithium. The relation to neutron elastic scattering is also established, and some measurements on liquid gallium can be interpreted in a qualitative manner. By studying the charge-charge correlation function for the two-component liquid metal, a theory of electrical resistivity is afforded, which is shown to reduce to Baym’s treatment of the scattering of electrons by the density fluctuations in the limit of weak electron-ion interaction. The relation between the high-frequency conductivity, obtained for arbitrary strength of the electron-ion interaction and the classical Drude-Zener theory is pointed out, and the sum rules for conductivity are seen to be related to those forSii(q, ω) in the limitq→0. A brief discussion of the thermodynamics of the two-component system is included, and related to results for weak electron-ion coupling.