| The bow-tie-shaped gold nanoantennas develop electric-field strengths in the gap through interactions with quasiparticles known as surface plasmons. (The field strength E is colour-coded) When a beam of argon atoms (green) is directed towards the gap, the field strips them of electrons, which subsequently recombine - a process that results in the generation of high harmonics of the original light, including the sought-after extreme ultraviolet radiation. (Data and calculations courtesy of J. Aizpurua; Image and text courtesy: Nature) |
