A few years ago, researchers decided to zero in on a superconducting metal called strontium ruthenate. Its structure is mysterious class It is a copper-based “copper oxide” superconductor, but it can be produced in a more natural way. Although the research team did not learn the secrets of copper oxide, the material reacted in ways that were incomprehensible to Ali Hussein, who refined the technique as part of his PhD.
Hussain found that the bouncing electrons took away their energy and momentum, indicating that the electrons were causing energy-draining ripples within the strontium ruthenate. However, the wave exceeded his expectations. The waves were 100 times too fast for sound waves (ripples through the nucleus of an atom) and 1,000 times too slow for electric charge waves spreading across the flat surface of a metal. They also had extremely low energy.
“I thought it must be an artifact,” Hussain said. So he put in another sample, tried another voltage, and even had another person measure it.
Ali Hussain developed a method to accurately measure the energy and path of bouncing electrons. These observations revealed the demon mode of strontium ruthenate.Photo: Matteo Mitrano
An unidentified vibration remained. After doing the calculations, the group found that the energy and momentum of the ripples closely matched Pines’ theory. The group knew that in strontium ruthenate, electrons move from atom to atom using one of three different channels. The researchers believe that in two of these channels, the electrons synchronize and neutralize each other’s motion, fulfilling the roles of the “heavy” and “light” electrons in Pines’ original analysis. I concluded. They discover a metal that has the ability to harbor the demons of the Pines.
“It’s stable in strontium ruthenate,” Abbamonte said. “It’s always there.”
The ripples don’t exactly match Pines’ calculations. And Abbamonte and his colleagues can’t guarantee they haven’t seen other, more complex oscillations. But other researchers say that overall, the group makes a strong case that the Devil of the Pines has been captured.
“They did the most honest checks they could,” he said. Sankar das Salmaa condensed matter theorist at the University of Maryland, pioneering work About the devil’s vibrations.
devil released
Now that researchers suspect the devil exists inside real metal, some can’t help but wonder if static motion has any real-world effects. . “They shouldn’t be uncommon and might do something,” Abbamonte said.
For example, sound waves rippling through a metal lattice bind electrons together in a way that causes superconductivity, a group of physicists suggested in 1981. devil’s vibration Superconductivity could be induced in a similar way. Abbamonte’s group initially chose strontium ruthenate because of its unconventional superconductivity. Maybe the devil is involved.
“It’s unclear at this point whether demons play any role,” Koger said. “But that’s another piece of the game.” (Physicists often think of waves with certain properties as particles.)
But the main novelty of this study is the discovery of a long-expected metal effect. For condensed matter theorists, the discovery brings a satisfying conclusion to a 70-year-old story.
“This is an interesting addendum to the early history of electronic gases,” Coleman said.
And for Hussain, who earned his degree in 2020 and now works at Quantinuum, the research is a strange phenomenon that physicists lack the equipment to understand in metals and other materials. This suggests that it is full of vibrations.
“They’re just sitting there, waiting to be discovered,” he said.
original story Reprinted with permission from Quanta Magazine, Editorially independent publication simmons foundation Its mission is to enhance the public’s understanding of science by covering research developments and trends in mathematics, physical sciences, and life sciences.
