Theoretical physicist Yashar Komiyani, an associate professor in the College of Arts and Sciences at the University of California, was involved in an international experiment using a strange metal made from an alloy of ytterbium, a rare earth metal. Physicists at a lab in Hyogo, Japan, fired radioactive gamma rays at a strange metal to observe its unusual electrical behavior.

The research, led by Hisao Kobayashi of Hego University and RIKEN, is published in the journal Science. The experiment revealed unusual fluctuations in the electrical charge of a strange metal.

“The idea is that in a metal, you have a sea of ​​electrons moving in the background in the ion lattice,” Komiani said. “But something amazing happens in quantum mechanics. You can forget about the complications of the ion lattice. Instead, they act as if they were in a vacuum.” For years Komiani has investigated the mysteries of strange metals in connection with quantum mechanics.

“You can put something in a black box and I can tell you a lot about what’s inside by just measuring things like resistance, specific heat and conductivity, without even looking at it,” he said. “But in the case of strange metals, I have no idea why they exhibit this behavior. The mystery is why charge oscillates so slowly in a strongly correlated quantum system.

“The mystery is, why does the charge fluctuate so slowly in a strongly correlated quantum system?” — Yashar Komiani, UC theoretical physicist

Strange metals are of interest to a wide variety of physicists who study everything from particle physics to quantum mechanics. One reason is their surprisingly high conductivity, at least at extremely low temperatures, giving them potential as superconductors for quantum computing.

“These new results are really exciting because they provide new insights into the inner workings of a strange metal,” said co-author Piers Coleman, a distinguished professor at Rutgers University.

“These metals form the basis of new forms of electronic matter – particularly exotic and high-temperature superconductivity,” he said. Coleman said it’s too early to tell which new technologies the strange metals might inspire.

“After Michael Faraday discovered electromagnetism, British Chancellor William Gladstone is said to have asked what good it would do,” Coleman said. “Faraday said he was confident that one day the government would tax it, though he didn’t know it.” Faraday’s discoveries opened up a world of innovation.

“We think about weird metal the same way,” Coleman said. “Metals play such a central role today – copper, the traditional metal archetype, is in every device, every power line, and around us.”

Strange metals could one day be ubiquitous in our technology, Coleman said. “The big question with strange metals is the origin of their scale invariance – their ‘quantum criticality,'” he said.

“As the experimenters try to reconstruct our results on other strange metals, our team at UC and Rutgers will try to put our new discovery into a new strange metal theory.” The experiment was groundbreaking in part because of how the researchers created gamma particles using a particle accelerator called a synchrotron.

“In Japan, they use a synchrotron like at CERN. [Європейська організація ядерних досліджень]The one that accelerates the proton and hits the wall and emits gamma radiation,” Komiani said. “So they have an on-demand source of gamma radiation without using radioactive material.”

The researchers used spectroscopy to study the effects of gamma rays on the strange metal. The researchers also examined the rate at which the metal’s electrical charge oscillates, lasting just one nanosecond (billionth of a second). This can seem incredibly fast, Komiani said.

“However, in the quantum world a nanosecond is an eternity,” he said. “We wondered for a long time why these oscillations were so slow. My colleagues and I theorized that they might be lattice vibrations, and indeed they are.