  We study localized plasmons at the nanoscale (nano-plasmons) in graphene. The
collective excitations of induced charge density modulations in graphene are
drastically changed in the vicinity of a single impurity compared to graphene's
bulk behavior. The dispersion of nano-plasmons depends on the number of
electrons and the sign, strength and size of the impurity potential. Due to
this rich parameter space the calculated dispersions are intrinsically
multidimensional requiring an advanced visualization tool for their efficient
analysis, which can be achieved with parallel rendering. To overcome the
problem of analyzing thousands of very complex spatial patterns of
nano-plasmonic modes, we take a combined visual and quantitative approach to
investigate the excitations on the two-dimensional graphene lattice. Our visual
and quantitative analysis shows that impurities trigger the formation of
localized plasmonic excitations of various symmetries. We visually identify
dipolar, quadrupolar and radial modes, and quantify the spatial distributions
of induced charges.
