Plasmonic Dielectric Response of Finite Temperature Electron Gas

Abstract: In this research we report the dielectric response of a finite temperature electron gas, electrostatically interacting with both external and self-induced plasmonic fields, in the well-known random phase approximation. The generalized energy dispersion relation which incorporates the plasmonic band structure is used to calculate the Lindhard dielectric response of homogenous electron gas from which many important physical functionals, such as the structure factor, loss function, screening potential, optical reflectivity and electronic stopping power are deduced. The present dual length-scale theory of dielectric response incorporates both single electron as well as collective electrostatic oscillation of electrons which, due to the Van-Hove-like singularity at plasmon wavenumber, shows distinct features of plasmonic response to electromagnetic interactions of the electron gas with arbitrary degree of electron degeneracy. It is shown that the static impurity charge screening potential is oscillatory Lennard-Jones-type attractive potential which is quite different from both predicted by the Conventional noninteracting Lindhard theory and the Shukla-Eliasson attractive potential obtained from quantum hydrodynamic approach. It is also revealed that due to resonant electron-plasmon interactions and multi-pole structure of the electronic response function the Landau damping region is scattered. The findings of current research may have important implications for a wide range of physical phenomena relevant to a broad nonrelativistic electron density-temperature regime, from the laboratory scale semiconductors and nanoelectronic technology to the warm dense matter state.