A magical material that could conduct electricity effortlessly at room temperature would potentially transform civilization, recapture energy lost due to electrical resistance, and open up possibilities for innovative technologies.
As yet The claim of such a room temperature superconductor After they were published in the prestigious journal Nature in March, some were skeptical, even suspecting that the results were fabricated.
But now, a group of researchers from the University of Illinois at Chicago reports that it has verified an important measurement: the apparent disappearance of electrical resistance.
This result doesn’t prove that the material is a room-temperature superconductor, but it may inspire other scientists to take a closer look.
Ranga P. Dias, professor of mechanical engineering and physics at the University of Rochester in New York and a key figure in the original research, pointed out that the material appears to be a superconductor at temperatures as hot as 70 degrees Fahrenheit – much hotter than other superconductors – when Squeezed at a pressure of 145,000 pounds per square inch, or about 10 times the pressure exerted at the bottom of the ocean’s deepest trenches.
The high pressure means the material is unlikely to find practical use, but if the discovery is true, it could point the way to other superconductors that actually work in everyday conditions.
This claim has been doubted because many scientific controversies have revolved around Dr. Dias, and other scientists who tried to replicate the results failed to detect any signs of superconductivity.
Dr. Dias has founded a company called Unearthly Materials to commercialize the research, which has raised $16.5 million in funding from investors to date.
revealed by new measurements a preprint paper Posted this month, Russell J., professor of physics and chemistry at the University of Illinois at Chicago. Came from a team led by Hemley. Dr Hemley declined to comment because the paper had not yet been accepted by any scientific journal.
Nevertheless, he is well respected in the field, and his report may lead to a more positive reconsideration of Dr. Dias’s superconducting claim.
“It may be reassuring to some people,” James J. said Hamlin, who has been a frequent critic of Dr. Dias’s research. “That makes me think there might be something to it.”
Dr. Dias’s material is composed of lutetium, a silvery-white rare earth metal, along with hydrogen and a small amount of nitrogen. Using a sample provided by Dr. Dias, Dr. Hemley’s lab made independent measurements of electrical resistance as the material was cooled under high pressure.
Dr. Hemley and his colleagues observed a sharp drop in the electrical resistance in the material. Although they occurred at temperatures up to 37 degrees Fahrenheit, which was about 30 degrees below the temperature Dr. Dias described, it would still be hotter than other superconductors. The transition temperature depends on how tightly the material was pressed.
“They did electrical resistance measurements to confirm our results,” Dr. Dias said in an interview. “This shows a pressure dependence of the transition temperature, which matches very well with what we reported in March in our Nature paper.”
Dr. Hamley’s measurements do not provide proof of superconductivity. It is possible that the material is only a very good conductor and not a superconductor.
The report did not include measurements to determine whether there was zero magnetic field inside. That phenomenon, known as the Meissner effect, is considered the definitive proof of a superconductor.
Some of Dr. Dias’s earlier papers have provoked heated debate. Critics, including Dr. Hamlin, say that sometimes important details about how the data from the experiments were processed were left out. magazine nature took back even a piece of paper Published in 2020, claiming an earlier superconductor, despite objections from Dr. Dias and other authors who say the findings are valid.
Dr. Hamlin also points out that Dr. Dias has a lot of cases Doctoral Thesis at Washington State University in 2013 Were copied theLiterally word for word, from the work of other scientists, including Dr. Hamlin’s own doctoral thesis.
Dr. Dias admits that he copied other people’s work in his thesis, saying he should have included the citation. He denies scientific error in his earlier papers.
Dr. Dias said, “I have never knowingly or intentionally engaged in plagiarism of anyone’s scientific work.” “It was a mistake.”
The research results of Dr. Hemley’s team argue that Dr. Dias has indeed discovered something new in the lutetium-hydrogen-nitrogen material.
Lilia Boeri, a professor of physics at Rome’s Sapienza University, said it was clear that this was not a repeat of a scientific scandal from two decades ago, when it was revealed that a researcher at Bell Labs in New Jersey, J. Hendrick Shawn, made my data In claiming a series of important discoveries.
Dr. Bori said of Dr. Dias, “It’s a completely different story in the sense that he certainly produced something and measured something.”
But, he added, “it’s really unclear whether this is a sign of superconductivity or simply that they’ve found some kind of interesting electronic transmission.”
In recent years, materials known as hydrides have proved promising in the search for superconductors that work at hot temperatures, although so far all of them have required crushing pressure. Dr. Dias said that it was the hydrides that led him to the lutetium-hydrogen-nitrogen mixture.
However, Dr. Boeri said that while other hydrides fit with the standard theory of superconductivity, Dr. Dias’s material did not.
an old paperDr. Hamley, Adam Denchfield, a graduate student in physics at the University of Illinois Chicago, and Hyowon Park, an assistant professor of physics at the same university, attempt to explain why researchers have overlooked subtleties in electronics. Structure of a lutetium–hydrogen–nitrogen compound that may provide an explanation of the high superconducting temperature.
He proposes that the elements of Dr. Dias’s material can be configured into different structures. The most prevalent structure may be responsible for the color change and other observed properties, while superconducting currents flow through small amounts of a different structure in the compound. This may explain why not all samples, even those made in Dr. Dias’s lab, are superconducting.
But Dr. Boeri is not impressed.
“The theoretical arguments are completely illogical,” he said. Dr Boeri said that materials with high superconducting temperatures require a very rigid lattice structure which this material does not have, and the paper does not discuss this issue.
Eva Zurek, a chemistry professor at the University at Buffalo who has collaborated with both Dr. Hemley and Dr. Dias on other projects, was initially skeptical but has now partially changed her mind.
Numerical simulations of superconductors involve simplifications to the calculations. Dr. Hemley’s paper argues that the calculations should be done somewhat differently, and when Dr. Zurek’s group tried those modifications, they arrived at the same answer.
“I realized it’s not impossible,” Dr. Zurek said. “I wouldn’t dismiss it right away, let’s just say it like that.”