Examining Plasmons with Polymer ScienceCategory: Science & Technology
Posted: July 12, 2012 04:43PM
Plasmons are an interesting quasiparticles made by the coupling of an electron and a photon. This coupling allows the energy and information of the photon to travel like an electric current across a piece of metal, at a much smaller size than possible with regular optics. Polymers on the other hand are molecules with a specific repeating structure and are incredibly common. Researchers at Rice University decided to study plasmons on gold nanoparticles that were arranged as though they were a polymer and found some interesting effects.
Like polymers, the properties of the connected nanoparticles were affected by their patterning. Having two rows of nanoparticles instead of one resulted in the plasmons not being able to travel as far. Curiously the size and disorder of the nanoparticles in the row(s) had some but impact on the plasmons, but not very much. This is important as it means minor defects to the nanoparticles will not greatly damage a plasmonic signal. Also the researchers found that once you have 10 nanoparticles connected together, the optical spectrum of the entire molecule stabilizes. This means that chains of nanoparticles even 50 particles long behave similarly to those that are just 10 particles long.
Plasmonics provide a link between optics and electronics that may one day be exploited for computing purposes. Eventually we may see plasmonic computers that take advantage of the quasiparticle's unique properties to mesh electronics and optics into something that operates at high speed, with little power.