LK-99: The room temperature superconductor that wasn’t

The summertime is a perfect time for things to trend across social media. One of the more surprising topics to get serious attention was the possibility of a room temperature superconductor that could pave the way for quantum computing and ultrafast high-speed trains.

So was LK-99, as it’s known, too good to be true? To understand, here’s a truncated version of the saga that had internet scientists atwitter over the last month.

It all started in late July when a team of researchers led by Sukbae Lee and Ji-Hoon Kim at the Quantum Energy Research Centre in Seoul, South Korea released a preprint paper about the discovery of a superconductor made of copper, lead, phosphorus and oxygen that works at room temperature and ambient pressure. The preprint was accompanied by a video of the compound in action. The name derives from Lee and Kim and the fact that the material was identified as a possible superconductor back in 1999.

What are superconductors?

“Superconductors have two properties,” Dr. Michael R. Norman, a distinguished fellow at Argonne National Laboratory, told Straight Arrow News. “They have zero resistance. So they carry current without any loss. The other thing is they have a tendency to expel magnetic fields. And so the combination of this means that not only can you make wires without current loss, you can use coils of superconductors that make the highest field magnets that we know.”

MRI machines in hospitals are one of the biggest applications for superconductors in their current form. For an MRI machine to function, magnetic coils are cooled to negative 270 degrees celsius using helium. The need to reach these low temperatures makes operating the devices very expensive.

What happened with LK-99?

While there was a lot of attention given to the prospect of a room temperature superconductor, the papers hadn’t been peer-reviewed and faced accusations of being published without the approval of two of its authors.

“I would guess that the reason the other two authors didn’t want it posted was they didn’t think it was quite there yet,” Norman added. “The paper needed to be polished, the data needed to be looked over some more, et cetera.”

Weeks after the initial reports, no other researcher has been able to replicate the findings. In fact, researchers found it was not a conductor at all, but an insulator.

A former Harvard researcher was able to replicate the phenomenon of the compound floating above a magnet, but he did so using a pellet of compressed graphite with iron shavings. It was not quite the room temperature superconductor that was promised.

Benefits of a room temperature superconductor

A room temperature superconductor would open up a wealth of possibilities including quantum computers.

“So you know you have your laptop. It works in terms of bits, on/off is zero/one,” Norman said. “So what happens in a quantum computer is the bit is a superposition of zero and one.”

Essentially they offer more computing power than even the most powerful supercomputers. But quantum computers can only be used for very specific tasks.

Room temperature superconductors would also allow for high speed maglev trains, which use magnets to levitate a train on a thin cushion of air above the tracks. These types of trains already exist. A train in China crossed 281 mph at a recent test, making it the fastest train in the world.

At the end of the day, Dr. Norman said these types of claims happen all the time and it’s part of what scientists do.

“This is one of the roles of scientists,” he said. “People make outstanding claims and then they’re worth checking out.”

He also cautioned people in believing that scientific breakthroughs like LK-99, if proven true, would make a tangible impact on everyday life immediately.

“If you look at some of the technology that’s going into the fusion reactor in France, for instance, and into the upgrade of the Large Hadron Collider, those materials were discovered in the 50s,” he says. “And just now in the last decade people are trying to make technological applications out of them, and those things are just alloys of niobium and tin. This material is far more complicated than that.”

But all of the attention in the last month was a welcome surprise for material physicists who don’t get the attention some of their peers in other fields enjoy.

“What we do in materials physics is not hyped like when we see these wonderful photos coming out of the James Webb Telescope,” Dr. Norman says. “But in fact, what we do in materials physics is allow for the laptop and the technology that we’re doing this conversation on. And so I think giving attention to the field is good. What we do with materials physics is we try to discover materials that will impact people’s lives. So I think this kind of attention can have a positive aspect to it.”