We present the main features of first principles numerical methods to describe plasmonic excitations in bulk and nanosized materials, and we apply these methods to a number of bulk and lower-dimensional nanosystems. Our main focus lies on graphene, which is an interesting numerical and experimental paradigm to study plasmonic excitations in a nanosystem with anisotropic and lossy dielectric functions. Beyond graphene we also discuss plasmonic excitations in similar two-dimensional nanosystems. In order to analyse more complex collective excitations of the electron gas in nanosystems, we take advantage of a fundamental relation between density fluctuations and the electron energy loss spectra (EELS), and suggest a general method to study noise in nanosystems.
The optical properties of photonic devices largely depend on the dielectric properties of the underlying materials. We apply modern ab initio methods to study crystalline SiO 2 phases, which serve as toy models for amorphous glass. We discuss the dielectric response from the infrared to the VIS/UV, which is crucial for glass based photonic applications. Low density silica, like cristobalite, may provide a good basis for high transmission optical devices.
Conference Committee Involvement (1)
Fiber Lasers and Glass Photonics: Materials through Applications