The additional boundary conditions that apply at the interface between two spatially dispersive media are derived from macroscopic models. For a metal-metal interface the hydrodynamic model is used, and for the general dielectric-dielectric interface an isotropic dielectric solid model is employed. It is found that if certain physically acceptable boundary conditions are used, the continuity of the normal component of the energy current density is automatically ensured. Thus, some previously derived additional boundary conditions, based on energy current arguments, are unnecessary. As an example the dispersion curves of the interface plasmon-polaritons at a potassium-aluminium boundary are calculated. © 1981.
Boardman, A. D., & Ruppin, R. (1981). The boundary conditions between spatially dispersive media. Surface Science, 112(1–2), 153–167. https://doi.org/10.1016/0039-6028(81)90339-3