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Standing on the edge of a ledge gives off an uncomfortable and unstable feeling. Likewise, researchers at the U.S. Department of Energy discovered that gold nanoparticles act unusually when placed close to the edge of one-atom-thick graphene sheets -- theorized to have major implications for the development and study of new sensors and quantum devices.  

n a study from Argonne, published in the journal Nano Letters, titled "Visualization of Plasmonic Couplings Using Ultrafast Electron Microscopy," researchers utilized the Ultrafast Electron Microscope at the U.S. DOE to look directly at coupling behaviors between gold nanoparticles and graphene.

Haihua Liu, a nanoscientist at Argonne, explains that surface plasmons are induced by light electron oscillations on the surfaces of nanoparticles or at the interface of nanoparticles and other materials, reports PhysOrg.  

In addition, when light is shone at nanoparticles, it creates a momentary plasmonic field. The pulsed electrons from the UEM interact with the plasmonic field moment when they overlap, with electrons either gaining or losing energy. Scientists collected the electrons that gain energy using energy filters to map out the distributions of plasmonic fields around the nanoparticles.  

When studying gold nanoparticles, the team of scientists discovered a bizarre phenomenon. When gold sat flat on the sheet of graphene, the plasmonic field was symmetrical. However, when there were positioned near the edge of graphene, the plasmonic field concentration was much stronger near the region's edge.

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