KNOXVILLE, Tenn. — The image of a physical phenomenon first seen and recorded by University of Tennessee physicists appears on the cover of the current issue of Nature.
Joe Carpinelli, a UT-Knoxville doctoral student, said the image is the first visual observation of a surface charge density wave. These waves occur when electrons rearrange on the surface of materials, he said.
Carpinelli, lead author of the article in Nature, said electrons move naturally to make a material more stable, but charge density waves had never been observed on the surfaces of materials.
“Surface charge density waves had not been definitively shown to exist prior to our observation,” Carpinelli said. “People have hypothesized that these waves occurred at the surface of materials, but most of the data suggesting existence of the waves has not been direct images.”
The scientists created the wave by placing a very thin layer of lead on a germanium crystal and cooling it, Carpinelli said.
The observation was made with a special microscope, said Carpinelli, who worked with Dr. Ward Plummer, UT-Oak Ridge National Laboratory Distinguished Scientist and Dr. Hanno Weitering, UT-Knoxville assistant professor.
Plummer said the work is a boost for the new field of solid state surface chemistry.
“The goal of this new field is to design thin films or interfaces on surfaces with unique properties,” Plummer said. “Carpinelli’s work points the way toward uncovering fascinating new physics.”
Nature is a leading scientific journal.
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Contact: Joe Carpinelli, Ward Plummer (423-574-7005)