• Yan, Jun
• Jacobsen, Karsten Wedel
• Thygesen, Ks

Abstract

First-principles calculations of the conventional and acoustic surface plasmons (CSPs and ASPs) on the (111) surfaces of Cu, Ag, and Au are presented. The effect of s-d interband transitions on both types of plasmons is investigated by comparing results from the local density approximation and an orbital-dependent exchange-correlation (xc) potential that improves the position and width of the d bands. The plasmon dispersions calculated with the latter xc potential agree well with electron energy loss spectroscopy (EELS) experiments. For both the CSP and ASP, the same trend of Cu <Au <Ag is found for the plasmon energies and is attributed to the reduced screening by interband transitions from Cu, to Au and Ag. This trend for the ASP, however, contradicts a previous model prediction. While the ASP is seen as a weak feature in the EELS, it can be clearly identified in the static and dynamic dielectric band structure.

Topics

• density
• impedance spectroscopy
• dispersion
• surface
• theory
• experiment
• density functional theory
• band structure
• electron energy loss spectroscopy