Scientists have finally hurdled 50 years of theories and failed attempts to prove the existence of a new form of matter: a condensate never before detected, now called excitonium.
The name excitonium was coined in the 1960s by Bert Halperin, a Harvard theoretical physicist who is now 76 years old. Peter Abbamonte, the physicist responsible for the discovery, saw him at a party and related that Halperin was excited, Newsweek reports.
Abbamonte, a physics professor at the University of Illinois at Urbana-Champaign, said,
It’s as close to ‘proved’ as you’re ever going to get in science. You can never really ‘prove’ anything, but, well, people find it convincing.
Excitonium is a condensate, or a solid, made up of particles called excitons, similar to how solid aluminum is made up of aluminum particles. However, the exciton particles are not created through as instinctual a process as other forms of matter.
Previous scientists had suspected that excitonium existed, but had no way of proving it. Abbamonte and his team invented an electron-scattering technique that would detect the end result of the exciton particles. They began by using a clean surface of the material in a vacuum, and scattered electrons from its surface to make waves.
The particular pattern the waves made when they spread allowed the scientists to find the escaped electrons in the form of excitonium. It’s rather similar to how the famous Higgs Boson was detected. The scientists call the method momentum-resolved electron energy-loss spectroscopy, or M-EELS.
Abbamonte and his colleagues began working on the scattering technique seven years ago, and it as not designed to detect excitonium. They wanted to study high-temperature superconductors, and it was through “total serendipity” in 2015, Abbamonte said, that they realized their work could potentially prove the existence of a new kind of matter.
Excitonium is currently such new ground that scientists don’t know much about it. “The most important thing is that it exists. It’s one of those things that just ought to be there, you know? And it didn’t make sense that it wasn’t,” Abbamonte said.
The study was published in the journal Science.