Tailoring plasmonic resonances of nanowires by corrugation and corners

We analyze the impact of different features of crosssection of metal nanowires on the plasmonic resonances. For weak periodic corrugations, the problem admits a full-scale analytical treatment revealing nontrivial properties. Numerical study shows nonlinear red shift of the main resonance with increasing modulation periodicity and amplitude. For nanowires with sharp corners of variable curvature, we predict the simultaneous occurrence of the fundamental phenomena: the main dipolar plasmonic mode experiences strong red shift with increasing corner curvature; for large curvature, the resonance is controlled by the apex angle of the corner; the split-off dipolar plasmonic mode experiences strong localization at the corners.