A team of researchers led by Peter Abbamonte, a professor of physics at the University of Illinois Urbana-Champaign, have finally found a demon particle 67 years after it was predicted.
Key points
- They used a nonstandard experimental technique that directly excites a material’s electronic modes, allowing them to see the demon’s signature in the metal strontium ruthenate.
- The demon isn’t actually a particle in the technical sense. Instead, it’s a plasmon, the aforementioned plasma wave, but it behaves much like a particle and appears to play a pivotal role in superconductors.
- Today, building superconductors (materials that have no electrical resistance) typically requires incredibly cold temperatures approaching absolute zero. Pines, however, predicted that his demon particle could be formed at room temperature.
- Room temperature superconductors are a “holy grail” of science because they could potentially allow us to move energy around with almost no loss.
- In 1956, theoretical physicist David Pines predicted that electrons in a solid can do something strange.
- While they normally have a mass and an electric charge, Pines asserted that they can combine to form a composite particle that is massless, neutral, and does not interact with light.
- He called this particle a “demon.”
- The discovery of a demon is particularly important for understanding superconductors. Because this quasiparticle is massless, it can form with any energy and potentially at any temperature.
- The standard theory of superconductors, known as the BCS theory, attributes superconductivity to an interaction between electrons and phonons, the natural vibrations given off by an atomic crystal lattice.
