When Sinéad Griffin of the Lawrence Berkeley National Laboratory in California had some new findings to share about a seemingly mysterious material that sent Twitter users into a frenzy, she didn’t have to do much to get a lot of attention.
The unusual material, named LK-99, has been shown to the world as a superconductor that will conduct electricity at room temperatures with zero resistance.
On Twitter — or X, as Elon Musk has named it — “LK-99” has become a trending topic in recent days, and enthusiasts have hailed what they believe is the long-sought-after holy grail of physics, one that will change every day. alive with new technologies to solve climate change and make levitating trains commonplace.
On Monday night, Dr. Griffin in the world of social media his findings a short post which contains only a link to his initial paper and an animated GIF of President Barack Obama dropping the microphone at the White House Correspondents Dinner in 2016.
The response was rhapsodic. The mic drop was interpreted by some X users as confirmation that the holy grail had been found.
Thus gave Dr. Griffin yet another twist in a roller coaster of chaos and deflation that has enthralled LK-99 fans for more than a week.
The saga began when a group of South Korean scientists, mostly working for a small start-up company named the Quantum Energy Research Center in Seoul, posted. two reports who described their method for making LK-99 and the measurements they said showed the material’s superconducting efficiency. (The name of the material comes from the initials of the last names of two of the scientists — Sukbae Lee and Ji-Hoon Kim — and the year 1999, when they say they first synthesized LK-99.)
Most notably, they provided a video showing a small sample floating slightly above the magnet. The levitation, the scientists said, demonstrated the Meissner effect, which ensures a zero magnetic field inside the superconductor.
Alex Kaplan, who graduated in physics from Princeton University, learned about LK-99 at Hacker Newsa news aggregation website.
“I was just shocked,” Mr. Kaplan said in an interview. “My jaw dropped to the floor, and I started calling every physics friend I knew.”
That night, he shared his excitement on Twitter.
In that tweet, which received more than 132,000 likes, Mr. Kaplan to a group of LK-99 fans who have sparked a social media frenzy over the past week. Most enthusiasts are not experts, however. Mr. Kaplan, for example, works as the head of coffee product at Cometeer, a company that sells flash-frozen coffee extract.
Scientists studying superconductivity and solid state physics have been quieter. They appreciate the curiosity — their work rarely draws a public frenzy — but they are puzzled as to why this particular room-temperature superconductor claim took off so quickly while many prior claims which has not proven to go out and leave without a thrill.
“It’s great to have public interest in solid state physics research,” said Dr. Griffin, “with due care that it is explained correctly and with the caveats that I think are necessary for some of this discussion. But I think it’s fun.”
Skepticism remains, as the data provided by Korean scientists so far lacks credibility, many experts say.
“It’s too early to conclude anything about superconductivity,” said Sankar Das Sarma, director of the Condensed Matter Theory Center at the University of Maryland. “That data is very suggestive, but it’s not compelling.”
Dr. Das Sarma posted a commentary on the center’s Twitter account. He pointed out, for example, that at the temperature at which Korean scientists claim LK-99 becomes a superconductor, the electrical resistance drops, but not to zero. In fact, the resistance of the material, made of the mineral apatite with some of the lead atoms replaced by copper, is about 100 times higher than pure copper and other good conducting metals.
The levitation video is also inconclusive, as non-superconducting materials including graphite can also partially float in the same way.
Last weekend, Mr. Kaplan, who started much of the initial uproar, posted a photo of a Magic 8 ball with the words, “Probably done.” Then he saw the role of Dr. Griffin.
In an interview, Dr. Griffin that his paper, titled “Origin of correlated isolated flat bands in copper-substituted lead phosphate apatite,” did not confirm the hype.
“I’m not describing superconductivity in these calculations, that’s for sure,” he said. Instead, his computer simulations show that replacing copper with apatite resulted in an unusual rearrangement of atoms. The amount of the crystal structure of the mineral actually decreases slightly. That appears to shift the electronic structure to one that can be conducive to superconductivity.
The electronic features, known as “flat bands,” look similar to those observed in high-temperature superconductors, a class of materials discovered in the 1980s. (The name — high-temperature superconductors — is somewhat misleading. They operate at temperatures hotter than previously observed, but still colder than any naturally occurring place on Earth.)
These features can facilitate strong interactions between many electrons, which can cause superconductivity – but not always.
Dr. Griffin concedes that electronic structure calculations are less certain than his findings about crystal shrinkage because of the vast number of electrons involved. “There are inherently a lot of estimates you have to make in doing this,” he said. “It’s not a precise calculation of what you’re measuring experimentally.”
A group of Chinese scientists posted a paper describe similar calculations that found a similar electronic structure.
“I really don’t get the fuss about his preprint,” said Douglas Natelson, a professor of physics at Rice University in Houston. “That’s not to say it’s wrong, it’s just that theorists and computational materials people often make preprints based on the latest claimed material of interest. There is nothing unusual about that.”
On Wednesday, followed by Dr. Griffin long thread of tweets deflating optimistic interpretations of the mic drop GIF.
The cycle of excitement and deflation repeated itself later in the day when scientists at Southeast University in Nanjing, China, reported that they synthesized LK-99 and measured zero resistance in one of the samples.
However, the reported zero resistance occurred when the sample was cooled to minus-260 degrees Fahrenheit, not to room temperature, and it was a gradual decrease in electrical resistance, not the sharp drop one would expect in a superconductor. The data also showed a decrease in resistance at higher temperatures, which Southeast University scientists attributed to impurities or an instrumental glitch.
Dr. Das Sarma was again unimpressed.
As in the original LK-99 papers, “Southeast also has no migration, only instrumental artifacts,” he wrote. in a tweet. “What is the purpose here? No one can fool nature.”
said Dr. Das Sarma that he knew that research groups of several well-known physicists were working to synthesize the material and make measurements to determine if LK-99 was really a superconductor.
“A claim of this magnitude needs to be scrutinized,” said Dr. Das Sarma. “And independent groups need to replicate in as many ways as possible before we can declare victory.”
He added, “I believe this can happen. But that doesn’t mean it’s already happened.”
