27 March 2014 Tunning the frequencies of plasmons

Doping gold nanodisks

“Tunable plasmons in atomically thin gold nanodisks” in Nature Communications In a recent study carried out by the Nanophotonics theory research group led by ICREA Professor ICFO Javier García de Abajo and with his former student Dr. Alejandro Manjavacas as first author, researchers were able to demonstrate that atomically thin gold metal films can sustain collective electron excitations (plasmons) of similar strength as those of metal nanoparticles of the same diameter. The scientific results have been published in Nature Communications.

When light couples strongly to small metal particles, it produces collective oscillations of its valence electrons known as plasmons. In this study, researchers have shown that such excitations exist and are intense in metal islands that are only one atom thick. They have also explored the possibility of using these plasmons to achieve electro-optical tunability at visible and near-infrared frequencies.

This leads to potential applications to optoelectronics, for example by changing the frequency of the plasmons through the increase in injected electrons. The small volume of the island maximizes the effect of any added electrons and produces large shifts in the plasmon frequency.

The results obtained in this study pose a great potential for the development of electrical visible and near-infrared light modulation in integrable, nano-scale devices, since the ability to modulate light at high speeds is of paramount importance for telecommunications, information processing and medical imaging technologies.