It may seem odd to think about using metallic structures for transmitting light because light quickly attenuates on passing through a metal, but light waves travelling only a few centimeters don't lose their energy and that discover could change the face of nanotechnology.
The discovery, known as acoustic plasmon, are surface plasmons formed by the group excitation of electrons but it is produced by the interaction between light and metal surfaces.
The advantage of acoustic plasmons over the long-known surface plasmons is that they are created with a different amount of energy. While common surface plasmons need 10 electron-volts of energy to become excited – too high for many technological applications – the acoustic plasmon can be triggered into an excited state with very low levels of energy input – less than 1 electron-volt.
Eugene Chulkov explains: "The charged waves that produces the light fall on the metallic surface in the same way as ripples are made by a stone thrown into a pond."
The research team has suggested baptizing the new phenomenon “the Silkin Plasmon” in recognition of the sterling work undertaken by scientist Slava Silkin, who works at the Donostia International Physics Center.
Research into this phenomenon could be useful in the design of metallic surfaces on a nanometric scale and on which the properties of the plasmons propagated by these surfaces, themselves, may be modified or manipulated.
This work has been led by physicist Pedro Miguel Etxenike, President of the Donostia International Physics Center, in collaboration with scientists from the CSIC, the UPV/EHU, the CIC Nanogune and the Universidad Autónoma of Madrid.
"Low-energy acoustic plasmons at metal surfaces", Bogdan Diaconescu, Karsten Pohl, Luca Vattuone, Letizia Savio, Philip Hofmann, Vyacheslav M. Silkin, Jose M. Pitarke, Eugene V. Chulkov, Pedro M. Echenique, Daniel Farías y Mario Rocca, Nature, doi:10.1038/nature05975.