Electron-energy-loss spectra of plasmonic nanoparticles.

We investigate electron-energy-loss spectroscopy (EELS) on metallic nanoparticles, through simulations, and provide a comprehensive comparison between EELS and the photonic local density of states (LDOS). Most importantly, we show that there is no direct link between EELS and LDOS maps, and that EELS can even be blind to hot spots in the gap between coupled nanoparticles. Although intimately related, the two quantities provide complementary information. This finding is in marked contrast to recently reported results.