One-click electromagnetism at the nanoscale
Very strong, because charge piles up at the sharp ends: at its longitudinal resonance an 80 × 20 nm gold spheroid in water concentrates the intensity about 34,000-fold (|E|²/|E₀|²) at its tips.
With an exact T-matrix solution for spheroids, for any aspect ratio, orientation and polarization; the map covers the field inside and around the particle.
A spheroid has rounded ends; real rods have flatter caps, which shift the resonance somewhat and change the tip field. The trends with aspect ratio and medium are the same.
Tip hot spots and fields of a nanorod or spheroid, from an exact T-matrix, in one click.