LK-99 is an online sensation, but it is not replicating as well as it could

The Unidentified Superconducting Object LK-99 is a Room-Temperature SUPERCONDECTOR, Says Dr. Yoon Kim

LK-99’s purported superconductivity drew immediate scrutiny from scientists. The researcher says that her first thought was “no.” The Unidentified Superconducting Objects are reliably shown on the arXiv. Every year or so there is a new one. Advances in superconductivity are often touted for their potential practical impact on technologies such as computer chips and maglev trains, but Vishik points out that such excitement might be misplaced. Widespread progress in superconductivity has had benefits for basic science, but very little for everyday applications. There’s no guarantee a material that is a room-temperature superconductor would be of practical use, Vishik says.

We could still potentially see some of the things that a room-temperature superconductor is supposed to usher in, even if it’s never discovered. Electricity grids and medical equipment are examples of efficient superconducting grids. Those developments might depend on more incremental improvements to make existing superconducting materials cheaper to manufacture and easier to deploy.

The research team, led by Sukbae Lee and Ji-Hoon Kim at the start-up firm Quantum Energy Research Centre in Seoul said in preprints published on 25 July1,2 that a compound of copper, lead, phosphorus and oxygen, dubbed LK-99, is a superconductor at ambient pressure and temperatures above 127 °C (400 Kelvin). The material expels magnetic fields, as well as zero electrical resistance, in the process of levitating above a magnet, which the team claims is a sign of superconductivity. Superconductivity can only be achieved in certain materials at high pressures or very low temperatures. No material has ever been confirmed to be a superconductor under ambient conditions.

“If it can’t be manufactured, it’s a laboratory curiosity — one that will win a Nobel Prize — but it’s still a curiosity. It’s a really long way from a material which everybody can get excited about as a physics experiment to something which an engineer will say, ‘Yes, I’m going to buy that and put it in my machine,’” Grovenor says.

Other big-name institutions have yet to share their results, including researchers at Argonne National Laboratory and FAMU-FSU College of Engineering. “Within a week or two, we’re going to have 20, 30, 40, 50, or 100 labs that will have done various syntheses. So it’s going to be clear pretty quickly,” says Larbalestier.

That is not in the best interests of 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 is accomplished by reproduction and by our ability to test each other’s results.

Redd Matter? The Rochester researchers discovered a superconductor made from nitrogen, hydrogen and rare earth metal lutetium and a fictional material that forms black holes

The Rochester researchers tried again. They published another paper on a room temperature superconductor made from nitrogen, hydrogen and rare earth metal lutetium in March. 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.

“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.”

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. The preprints show zero electrical resistance, so it is difficult to say whether LK-99 is a very good conductor or a perfect superconductor. “Metal is a really, really, really, really, really good conductor,” Mason says. But it’s still not perfect. You don’t use much energy in the 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 heat anomalies test is used by major laboratories to study these kinds of materials. All superconductors that have been proven to be superconductors have shown this specific heat anomaly. “If there is no specific heat anomaly, it ain’t a superconductor.”

There are inconsistencies in the data and the preprints disagree with each other. There is conflict between the authors with three of them 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. The author of the paper didn’t respond when The Verge contacted them.

Efforts to duplicate those preprints are very important at the moment. That issue is only one of the many issues that give experts pause. They had more than one concern in interviews with The Verge.

Claimed Superconductor LK-99 is an Online Sentiment — but Replication efforts Fall Short. Source: A Physicist’s Perspective

LK-99 can look like an old dark gray rock, but in actuality it is a polycrystalline material made out of lead, oxygen, and phosphorus that has been infused with copper. In late July, a group of researchers published papers about the discovery of LK-99 and called it a new historical event that opens a new era for humankind.

Scientists are frustrated by the atmosphere of hype and have decided to mimic the levitation videos with everyday materials suspended by string. “I opened Twitter up one day and noticed a bunch of sketchy videos with little floating pebbles,” says Eric Aspling, a physicist at Binghamton University in New York. In response, he uploaded a video featuring a “sample of LK-99 shaped as a fork” suspended by tape. “I thought, ‘How can anybody be convinced by this?’,” he says.

The limited success of the replication attempts has not quelled speculation online. Unverified videos of samples, supposedly levitating because of superconductivity, have circulated as viral evidence, despite the fact that many materials — including graphene, frogs and pliers — can exhibit similar magnetic behaviour.

The material would not display room-temperature superconductivity if the feature is confirmed in future experiments. Flat bands of different materials are related to superconductivity, which can be seen in the fact that some of the materials are slightly offset sheets of atomically thin carbon. But this does not show superconductivity above 127 C in the lead-based LK-99, Schoop says.

Source: Claimed superconductor LK-99 is an online sensation — but replication efforts fall short

Flat band quantum materials: LK-99 (a lead phosphate crystal) confesses to having ‘flat bands’, as predicted by an anonymous online micro-messaging site

Griffin agrees that knowing the structure is essential. But she says that the structure found by the Korean team is similar to that of other lead phosphate minerals. It is realistic to think it is possible.

Other theory papers also suggested the presence of flat bands, but all of them suffer from the same assumption about the structure, says Leslie Schoop, a solid state chemist at Princeton University in New Jersey. She does not believe in the DFT before she knows the correct crystal structure.

A theoretical analysis posted on the micro-messaging site prompted excitement among online enthusiasts. An image of Barack Obama doing amic drops was used in the theory paper by Sinead, who studied quantum materials at Lawrence Berkeley National Laboratory. The optimism was prompted by Griffin’s use of DFT to find that LK-99 has ‘flat bands’, a feature that indicates electrons in the material are strongly correlated with each other. “Flat band systems tend to show interesting physics,” Vishik says. “So when a material is predicted to have a flat band, people get kind of excited.”

Robert Palgrave, a chemist at University College London, claims that the materials in both teams are different from the original. The Korean team has two different X-ray diffraction patterns. The members of the team did not reply to the request for comment.

The Korean team’s sample was smaller than the National Physical Laboratory one, according to Veerpal Singh Awana, a co-author. “Our LK-99 is very similar to that as the reported superconducting LK-99,” he says.

To confirm that material’s structure and identity, replicators used X-ray diffraction, an atomic imaging technique. The Beihang team concluded that their sample’s structure was “highly consistent” with that of LK-99.