Hidden Structure of Plasmons

Plasmons are collective oscillations of the electric charges within a material. Models of plasmons typically describe them as simple waves in the electron density, but new theoretical work suggests that the currents within plasmons could be more complex than expected. Li-kun Shi and Justin Song from the Agency for Science, Technology and Research in Singapore investigated plasmons in a 2D metal exposed to a magnetic field. Their calculations show that the local current density can develop textures that resemble the hedgehog-like spin configurations in certain magnetic materials. This hidden structure may lead to a shift in the position of a plasmon when it reflects off a boundary.