Claims of revolutionary superconductor LK-99 are meeting resistance. Here's what you need to know

Limitless clean energy, portable MRIs,more efficientquantum computing these are just a few of the breakthroughs that could be made possible by the discovery of a superconductor that works at room temperature.

"If you made a room-temperature superconductor tomorrow ... you'd be famous, you'd win the Nobel Prize," saidDamian Pope, senior manager of scientific outreachat the Perimeter Institute for Theoretical Physics in Waterloo, Ont.

So it is no wonder that social media is abuzz with news of LK-99, a material that purportedly acts as a superconductor at ambient pressure and temperatures as high as 127C. A photo of the material levitating over a magnet caught many people's attention, though experts have said this is no guarantee of superconductivity.

Meanwhile, researchers around the world, as well as some (ill-advised) amateur home scientists, are racing to replicate the results. So far, none have produced LK-99 and observed superconductivity.

This is only the most recent in a long line ofclaims about this "holy grail"of materials science, as Pope described it which might explain why experts are approaching LK-99 with sentiments ranging from skepticism to cautious optimism.

"The public should be excited, but I think a certain amount of questioning iscalled for," said Alannah Hallas,a principal investigator at the Stewart BlussonQuantum Matter Institute at the University of British Columbia in Vancouver.

What is the claim?

At the end of July, ateam of researchers atthe Quantum Energy Research Centre, a startup in Seoul,published twopapers that have not undergone peer reviewon arXiv(pronounced "archive"), a pre-print server where scientists frequently report preliminary results.

The papers described LK-99, a newcopper-substituted lead apatite a compound consisting of copper, lead, phosphorus and oxygen. It is named after two of the researchers who discovered it and the year they say they first synthesized it.

What is particularly exciting about this claim is the relative ease of synthesizing the material, Hallas told CBC News in an interview.According tothe published methods, LK-99 was created through solid-state synthesis. Shecompared the process to baking, but simpler, "because there's no wet ingredients."

"You just mix together your powder reagents, and you use a mortar and pestle typically to homogenize themto get everything mixed up very well," said Hallas, who is also an assistant professor in UBC's physics and astronomy department. "Then you put it in the oven."

Experts also emphasized that the researchers haven't done anything incorrectly. It's common practice to upload preliminary findings to a pre-print server, especially when it's potentially a major breakthrough.

"If I believed that I had a room-temperature superconductor sitting in my lab ... I also would probably post it on [arXiv] as fast as humanly possible," Hallassaid. "That is such a monumental discovery that could change the world ... and thenthe scientific process will work as the scientific process does."

What is a superconductor?

A material must have two key properties to be considered a superconductor. Below some critical temperature, itmust expel all magnetic fields, through what's known as the Meissner effect, and conductelectricity with zero resistance meaning absolutely no energy is lost.

Hallas explained that at the atomic level, superconductors work because electrons pair up andstop behaving like electrons.

"Think of it as people dancing in a bar or in a nightclub," shesaid. "In a normal metal, everyone is dancing by themselves and ... doing their own thing. And maybe they're, like,bumping into each other and hitting elbows.

"Asuperconductor is like a scene in a movie where a flash mob comes out and everyone knows all the dance moves and they're dancing perfectly in sync. And so no one is bumping into anyone [and no energy is lost]."

So far, scientists have only been able to develop materials that keep those propertiesat extremely low temperatures or extremely high pressures, limiting their application and making them expensive to implement.

Superconductivity was first discovered over a century agobyDutch physicist Heike Kamerlingh Onnes. He found that solid mercury becomes a superconductor at about269 C just four degrees above absolute zero.In the following decades, more superconducting materials were discovered with similar critical temperatures.

The next major breakthrough didn't come until the 1980s, with the discovery of cuprate compounds a class of copper-containing materials that can act as superconductors at much higher temperatures, up to about140 C.

Physicists hope that the next jump will be to a material that can function as a superconductor at room temperature.

Why does this matter?

The applications of a room-temperature superconductor could be revolutionary, experts say.

"One that's really exciting for Canadians is applications in MRI machines," Hallas said. "MRIs use superconducting magnets to produce a strong magnetic field, which is the basis of the imaging."

Current MRI machines useniobium-titanium to generate that field, but it needs to be held at temperatures within 10 degrees of absolute zero. "I'm from Winnipeg, and that's significantly colder than even Winnipeg will get on the coldest day," she said.

Using a room-temperature superconductor would remove the need for liquid helium to keep the magnets cool, potentially paving the way for portable MRI machines that could be brought into remote communities.

Subir Sachdev, a professor of physics at Harvard University in Cambridge, Mass., is most excited about another potential application:fusion power, which promiseslimitless clean energy by imitating what happens in the core of stars like the sun.

"To achieve fusion, you have to take this plasma of charged particles protons and neutrons and so on and compress them in a small volume," hesaid in an interview with CBC News."Magnetic fields are what you'd use to do that."

Sachdev said it has already been proposedthat existing superconductors could make fusion a reality, but having room-temperature superconductors would make it that much easier.

For Pope of the Perimeter Institute, it's also important not to overlook what this could mean for our infrastructure. "Those big overhead transmissionlines that you see, about 15 per centof the power is lost from the power generating station till it gets to your home. [If we] replaced all of those wires there with superconducting wires, the amount lost would be zero."

For the same reason, computers could become hundreds of times faster and moreenergy-efficient, with no more energy lost as heat.

Why are physicists skeptical?

This is not the first unidentified superconducting object (USO)to appear on arXiv.

"Every few years there's some claim of a new material that suddenly is a better superconductor," Sachdev said. "The last time that really turned out to be true was in 1987," with the discovery of cuprate compounds.

Pope had a similar sentiment,adding that "it'skind of a quantum leap" to go from materials that superconduct at 140 C to over 100 C.

When it comes to the photo that captured attention on social media, Hallassaid it's important to remember that "there are other physical explanations that can lead to magnetic levitation."

"If you go on Amazon, you can purchase for under $100 a levitating flower pot, and that has nothing to do with superconductivity. That's actually just magnetic repulsion."

Hallasalso noted that the papers didn't contain everything you wouldtypically see in a peer-reviewed journal, and some of the reported structure gave her pause.

"The actual characterization of the final material is really incomplete.... Itdoesn't really pass the sniff test in terms of the sort of intuition of how that chemical reaction would unfold. It kind of involves some sort of unphysical configurations."

What ifLK-99 is the real deal?

Let's say, in the next few weeks, labs around the world are able to replicate the published methods, reproduce the results and provide independent confirmation that LK-99 is, indeed, a superconductor. Does that mean that all of these innovations areright around the corner? Not quite.

Hallas said although the straightforward method to synthesizeLK-99 means production seems very achievable on an industrial scale, "that's only the first step in a material actually kind of coming to fruition in terms of a usable technology." Other considerations include safety, cost, ability to withstand different environmental conditions and ease of fabrication into different configurations like wires.

Still, regardless of what happens with LK-99, researchers are happy to have some attention placed on materials science.

"I've never experienced anything like this in my research field, to see the general public become so excited about a reported discovery," Hallassaid. "It's giving a real snapshot of what our day-to-day process looks like and and what goes into the type of science that we're doing."