are shot into the metal to observe its features. The method also allows for the detection of plasmons, but the researchers found something more: an electronic mode with no mass.
This piqued the interest of the researchers, who even laughed off the possibility that they had found Pines' demon. However, as they began pouring over their data to discover the reasons for their observations, they found two electron bands oscillating out of phase, much like Pines described nearly seven decades ago.
Abbamonte's team was not explicitly looking for Pines's demon, but the physics professor does not believe it was all a "serendipitous" discovery. In the university press release, he emphasized that his team used a not-so-widely employed method on a not-so-widely studied substance. They were bound to find something new and significant because they were doing something different.
“It speaks to the importance of just measuring stuff,” he said. “Most big discoveries are not planned. You go look somewhere new and see what’s there.”The characteristic excitation of a metal is its plasmon, which is a quantized collective oscillation of its electron density. In 1956, David Pines predicted that a distinct type of plasmon, dubbed a ‘demon’, could exist in three-dimensional metals containing more than one species of charge carrier.