Pseudopotential theory of thek-dependent plasmon line width in simple metals

The nearly free electron pseudopotential theory is used to calculate thek-dependent plasmon linewidth that results from the decay of plasmons via interband transitions. The theory predicts the linewidth to be anisotropic in crystalline systems fork 0. Local field effects are included, but are found to give very small contribution. A detailed analysis of the behaviour of the linewidth of Al is given and very good agreement with recent experimental data is obtained.