Spin-dependent plasma frequency from all-electron ab initio calculations including spin-orbit coupling

We present a first-principles methodology to calculate spin-dependent plasma frequency. Electronic structure and plasma frequency of nine metals (Al, Au, Ag, Cu, Pd, Pt, Na, Fe, and Co) are studied using density-functional theory in an all-electron full-potential framework. The results are compared to pseudopotential approaches and experiments. We find a significant difference between the spin-up and spin-down contributions to plasma frequency. Thus, spin-polarization effects are important for understanding optical properties of metals. Spin-orbit coupling inclusion affects plasma frequency since it contains an interaction term between spin-up and spin-down electrons.