/cdn.vox-cdn.com/uploads/chorus_asset/file/24830078/Screenshot_2023_08_04_at_11.15.45_AM.png "Experts weigh in on the viral phenomenon of the LK-99 ‘superconductor’")
If you believe the hype, LK-99 could be revolutionary. It’s supposed to be a perfect superconductor that could help nuclear fusion become a reality and make levitating trains an easy way to commute. At least that’s the story that’s drummed up on social media — but it’s not what many experts think of the new discovery.
The frenzy has picked up steam on Twitter (which is currently rebranding to X), Twitch, and Reddit, where LK-99 has been heralded as the physics breakthrough of a lifetime. Academic researchers and eager amateurs alike are racing to see if LK-99 is legit by making it themselves. That way, they can figure out if LK-99 really has the superpowers that the researchers who first discovered it wrote about in controversial papers they published in July.
That’s the story that’s drummed up on social media — but it’s not what many experts thinkThe Verge spoke with a handful of experts in the field to try to sort the science from the hype. As much as they might love to see this kind of superconductor be successful — one that can conduct electricity with zero resistance in room temperature and ambient pressure — they’re skeptical. To be sure, we’re still waiting for more definitive answers from everyone trying to verify the claims about LK-99. The Verge also wanted to know — if LK-99 actually does what it’s supposed to — what comes next?
It may look like any old dark gray rock, but technically, LK-99 is a polycrystalline material made out of lead, oxygen, and phosphorus that’s been “doped” — or infused — with copper. A group of researchers kicked off a frenzy in late July when they published a set of papers about the discovery of LK-99 and called it “a brand-new historical event that opens a new era for humankind.” The papers, with lead authors from the Quantum Energy Research Centre in South Korea, claim that LK-99 is the world’s first room-temperature ambient-pressure superconductor. In other words, it can conduct electricity without any resistance in a typical setting. To go Sith Lord on the topic, eliminating resistance is everything. Power grids and electronics waste tons of electricity today because of resistance in less efficient materials.
Why is LK-99 potentially so important? There are other superconductors today. They’re used in magnetic resonance imaging (MRI) machines, quantum computers, and nuclear fusion devices. But those superconductors only work under very low temperatures or high pressures. That makes them too difficult and expensive to use in most everyday applications. “A technologically viable room-temperature superconductor isn’t just Nobel Prize territory. If you’ve patented it, it’s incalculable value essentially,” says Chris Grovenor, professor of materials at the University of Oxford and director of the Centre for Applied Superconductivity. “It’s transformational on so many things.”
“A technologically viable room-temperature superconductor isn’t just Nobel Prize territory. If you’ve patented it, it’s incalculable value essentially.”
Why has the scientific community reacted with skepticism? To start, LK-99 rose to fame after it was described in preprints, research papers that haven’t been subject to peer review. The gold standard, more or less, for new research is to be published in a reputable peer-reviewed journal. Two preprints were published in late July on the server arXiv, and a related study was published in the Journal of the Korean Crystal Growth and Crystal Technology earlier this year. That makes the efforts we’re seeing now to try to duplicate the findings in those preprints crucial. But that isn’t the only issue that gives experts pause. They raised a range of concerns in interviews with The Verge.
To start, there were inconsistencies in the data; the two preprints disagree with each other. There’s reportedly also conflict between the authors (there are three authors named on one paper and six on the other). The preprint with fewer authors contains “many defects,” an author of the other paper told New Scientist. The author, William & Mary physics research professor Hyun-Tak Kim, also said that the preprint was uploaded to arXiv without his permission. Kim and other corresponding authors of the papers did not respond when The Verge reached out to them.
Wait, there are more red (or at least yellow) flags… Grovenor points out that the researchers didn’t perform a heat anomaly test that’s standard for major laboratories studying these kinds of materials. “All superconductors that have ever been proven to be superconductors show this specific heat anomaly,” he says. “If there is no specific heat anomaly, it ain’t a superconductor.”
The preprints are also imprecise in their definition of “zero” resistance, according to Nadya Mason, a condensed matter physicist at the University of Illinois Urbana-Champaign. Superconductors should have zero electrical resistance, but the preprints show “zero” on a scale that makes it difficult to tell whether LK-99 is truly a perfect superconductor or just a very good conductor. “Metal is a really, really, really, really, really good conductor,” Mason says. But it’s still not perfect. “You do lose a lot of energy in heat. That’s why our laptops get hot and why you lose so much energy in the power grid. So it really matters whether you have a perfect conductor or a really good conductor.”
The building blocks for LK-99 raised some eyebrows, too. Unlike many superconductors made from metal, it starts out as a nonconducting mineral. “When you start with a rock, chances are you will end with a rock,” says Michael Norman, a distinguished fellow and former director of the materials science division at Argonne National Laboratory. Doping the material with copper is supposed to be what transforms it, but it’s not clear where the copper is supposed to go and how it manages to transform the rock into a superconductor.
“This discovery is completely out of the blue,” says David Larbalestier, chief materials scientist of the National High Magnetic Field Laboratory and professor at FAMU-FSU College of Engineering. “I have no idea what the idea, frankly, behind doping this [mineral] with copper was.”
Didn’t we hear about some drama over a room-temperature superconductor before LK-99? There has indeed been a lot of drama. Back in 2020, a team of researchers from the University of Rochester said they had found a room-temperature superconductor made from hydrogen, sulfur, and carbon. But the research, published in the prestigious journal Nature, was later retracted after editors pointed to issues with how the study’s data was processed.
“It makes most of us very, very wary of claims and cases where people can’t reproduce their data” The Rochester researchers tried again. In March, they published another paper on a room-temperature superconductor made from nitrogen, hydrogen, and the rare earth metal lutetium. They called it “reddmatter” after a fictional material in Star Trek that forms black holes. That paper is still under scrutiny, especially since one of the key researchers from Rochester faces separate allegations of plagiarism and data fabrication in his other work.
“That’s just not good for the field. And it makes most of us very, very wary of claims and cases where people can’t reproduce their data.” Mason says. “Science works by reproduction and by our ability to be open with each other and test each other’s results.”
How successful have efforts been to replicate LK-99 and show whether it’s superconducting? It’s not just big research labs that are working to see whether LK-99 can live up to the hype. Since LK-99 is made from relatively simple ingredients and doesn’t require extreme temperatures or pressures, other folks with access to it and the right equipment are trying their hand. An engineer at a space research startup has been livestreaming his efforts on Twitch, Wired reported this week (it was offline when The Verge tried to tune in).
Experts tell The Verge it’s still too soon to make a final call on LK-99. Nevertheless, some early results have captured people’s imaginations on social media. A video has been making the rounds online of a piece of LK-99, made by a research team from Huazhong University of Science and Technology, appearing to levitate. Floating when placed above a magnet is a sign of diamagnetism, when a material expels a magnetic field. It’s a classic signature of a superconductor, through a phenomenon called the Meissner effect, and the authors who first wrote about LK-99 also included a video of it partially levitating.
What’s important to keep in mind is that levitation alone doesn’t make something a superconductor. It still has to show zero electrical resistance in rigorous testing. Other things levitate because they’re diamagnetic.