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Plasmons
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 Electrons Ripple Across Atom-Thin Layers of Carbon

With a beam of infrared light, scientists have sent ripples of electrons along the surface of graphene and demonstrated that they can control the length and height of these oscillations, called plasmons, using a simple electrical circuit.
This is the first time anyone has observed plasmons on graphene, sheets of carbon just one atom thick with a host of intriguing physical properties, and an important step toward using plasmons to process and transmit information in spaces too tight to use light.

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Plasmon rulers
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Plasmon rulers measure in 3D

Researchers in the US and Germany have used a plasmon ruler to show in principle how to measure the three dimensional position of objects at the nano-scale. The ruler, which consists of a stack of gold nano-rods, could one day be used to improve understanding of soft matter processes, such as protein folding.
Plasmon rulers consist of metal nanoparticles that are attached to biomolecules. Like tiny antennae, the nanoparticles create plasmon resonances - waves of electrons - that absorb or scatter light at specific visible or infrared frequencies. Because the exact frequency depends on the proximity of other particles, the nanoparticles offer a way to measure inter-particle distance.
In the past, such distance measuring has been limited to one dimension, which has generally ruled out determining the relative orientation of the particles. But now Paul Alivisatos and Na Liu of the University of California at Berkeley, US, together with colleagues at the University of Stuttgart in Germany, have found a way to explore the other two dimensions.

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