
Light triggers gold in unexpected way - dnetesn
https://phys.org/news/2018-11-triggers-gold-unexpected.html
======
basicplus2
[https://en.m.wikipedia.org/wiki/Plasmonic_nanoparticles](https://en.m.wikipedia.org/wiki/Plasmonic_nanoparticles)

Plasmonic nanoparticles are particles whose electron density can couple with
electromagnetic radiation of wavelengths that are far larger than the particle
due to the nature of the dielectric-metal interface between the medium and the
particles

[https://en.m.wikipedia.org/wiki/Surface_plasmon](https://en.m.wikipedia.org/wiki/Surface_plasmon)

Surface plasmons (SPs) are coherent delocalized electron oscillations that
exist at the interface between any two materials where the real part of the
dielectric function changes sign across the interface (e.g. a metal-dielectric
interface, such as a metal sheet in air). SPs have lower energy than bulk (or
volume) plasmons which quantise the longitudinal electron oscillations about
positive ion cores within the bulk of an electron gas (or plasma).

[https://en.m.wikipedia.org/wiki/Plasmon](https://en.m.wikipedia.org/wiki/Plasmon)

In physics, a plasmon is a quantum of plasma oscillation. Just as light (an
optical oscillation) consists of photons, the plasma oscillation consists of
plasmons. The plasmon can be considered as a quasiparticle since it arises
from the quantization of plasma oscillations, just like phonons are
quantizations of mechanical vibrations. Thus, plasmons are collective (a
discrete number) oscillations of the free electron gas density. For example,
at optical frequencies, plasmons can couple with a photon to create another
quasiparticle called a plasmon polariton.

