Plasmons in Nanostructured Graphene

Licentiate thesis, 2015

Plasmons, collective electron density oscillations, provide physicists with intriguing challenges and possibilities. The inherent many-body properties of the plasmons together with their ability to localize light into small volumes make the plasmons interesting from both a purely theoretical viewpoint and an applications point of view. Graphene, with its rather special electronic properties, provides the field of plasmonics with a new material that exhibits large localization of the electric field together with low losses. In this thesis we cover the basic theory underlying modern theoretical plasmonics research. We do so in the context of linear response functions and the Random Phase Approximation that are standard tools in the field. We apply the theory to plasmons in different contexts, trying to highlight differences and similarities between graphene plasmons, plasmons in 2DEG's and conventional interface plasmons. We present light scattering results from a nanostructured graphene surface, tailored specifically to allow plasmon excitation. We investigate the reflection, transmission and absorption of such surfaces and also analyze the plasmon resonances that arise.