We have measured plasmon energies in Na under high pressure up to 43 GPa using inelastic x-ray scattering (IXS). The momentum-resolved results show clear deviations, growing with increasing pressure, from the predictions for a nearly free-electron metal. Plasmon energy calculations based on first-principles electronic band structures and a quasiclassical plasmon model allow us to identify a pressure-induced increase in the electron-ion interaction and associated changes in the electronic band structure as the origin of these deviations, rather than effects of exchange and correlation. Additional IXS results obtained for K and Rb are addressed briefly.
|Number of pages||5|
|Journal||Physical Review Letters|
|Early online date||16 Aug 2011|
|Publication status||Published - 19 Aug 2011|
- high pressure
- inelastic x-ray scattering
- alkali metals