Scientists discover the elusive ‘demon particle’ nearly 70 years after it was first predicted – and it could be the ‘holy grail’ of superconductors

Scientists have discovered a ‘demon particle’ that could lead to superconductors that conduct electricity at room temperature – the ‘holy grail’ of physics.

A superconductor is a certain metal or alloy that can conduct electricity without resistance, but it must be more than 100F below freezing to work.

Researchers at the University of Illinois recently identified a massless particle, meaning it can form at any temperature, in the metal strontium ruthenate — nearly 70 years after “demons” were first predicted.

Superconductors are used in operations such as levitating trains and high-precision magnetic resonance imaging (MRI) machines, but materials that operate at room temperature would pave the way for more powerful computers.

Superconductivity was discovered over 100 years ago in mercury cooled to the temperature of liquid helium at minus 452F.

After the discovery of superconductivity in mercury, the phenomenon was also observed in other materials at very low temperatures.

The materials included various metals and an alloy of niobium and titanium that could easily be made into wire

The demon particle was first predicted by theoretical physicist David Pines in 1956, who believed that electrons would react “strangely” as they travel through a solid.

Electrons can lose their individuality in solids because electrical interactions cause the electrons to combine to form collective units.

With enough energy, the electrons can form compound particles called plasmons with a new charge and mass determined by the underlying electrical interactions.

However, the mass is usually so great that plasmons cannot form with the available energies at room temperature – but Pines theorized there was an exception to this.

The physicist argued that if a solid has electrons in more than one energy band, as many metals do, their respective plasmons can combine in an out-of-phase pattern to form a new plasmon that is massless and neutral – a demon .

Since demons are massless, they can form with any energy and can exist at all temperatures.

However, the elusive demon particle accidentally discovered in a specific metal is massless, meaning it can form at any temperature. Pictured is a model of the demonic particle

This has led to speculation that they have essential effects on the behavior of multiband metals.

The discovery was made by a team of researchers led by Peter Abbamonte, a professor of physics at the University of Illinois Urbana-Champaign, who identified Pines’ prediction while studying the metal strontium ruthenate.

The experiment was not related to superconductors, but the metal resembles high-temperature superconductors without being one.

Researchers conducted the first investigation into the metal’s electronic properties by blasting it with electrons, summoning the demon in the metal’s characteristics.

Abbamonte worked on the project with a former graduate student Ali Husain, who said, “At first we had no idea what it was.

Demons are not in the mainstream. The opportunity came up early on and we actually laughed about it.

“But as we started to rule things out, we started to suspect that we really had found the demon.”

Edwin Huang, a Moore Postdoctoral Scholar at UIUC and a condensed matter theorist, was eventually asked to calculate the characteristics of the electronic structure of strontium ruthenate.

“Pines’ prediction of demons requires rather specific conditions, and it was not clear to anyone whether strontium ruthenate should have a demon at all,” Huang said.

‘We had to make a microscopic calculation to clarify what was going on. When we did this, we found a particle consisting of two electron bands oscillating almost equally out of phase, just as Pines described.’