Bulk plasma waves in a randomly inhomogeneous conductor

Abstract

The modification of the spectrum and damping of bulk plasma waves due to three dimensional random inhomogeneities of the density of a degenerate electron gas in a conductor have been investigated using the averaged Green's function method. The dependences of the frequency and damping of the averaged plasma waves, as well as the position ν m and width Δν of the peak of the imaginary part of the Fourier trans form of the averaged Green's function, on the wave vector k have been determined in the self consistent approximation, which makes it possible to take into account multiple scattering of plasma waves by inhomo geneities. It has been found that, in the long wavelength region of the spectrum, the decrease revealed in the frequency of the plasma waves is caused by the inhomogeneities, which agrees qualitatively with the behavior of the position of the peak ν m . In the range of large values of the correlation length of inhomogeneities and small values of k, the damping of the plasma waves tends to zero, whereas the width of the peak Δν remains finite, which is due to the nonuniform broadening. A comparison with the data of numerical calculations has been performed.