Nature retracts controversial superconductivity paper by embattled physicist
Physicist Ranga Dias is underneath investigation by his establishment, the College of Rochester in New York.Credit score: Lauren Petracca/New York Occasions/Redux/eyevine
Nature has retracted a controversial paper1 claiming the invention of a superconductor — a fabric that carries electrical currents with zero resistance — able to working at room temperature and comparatively low stress.
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The text of the retraction notice states that it was requested by eight co-authors. “They’ve expressed the view as researchers who contributed to the work that the revealed paper doesn’t precisely replicate the provenance of the investigated supplies, the experimental measurements undertaken and the data-processing protocols utilized,” it says, including that these co-authors “have concluded that these points undermine the integrity of the revealed paper”. (The Nature information group is unbiased from its journals group.)
It’s the third high-profile retraction of a paper by the 2 lead authors, physicists Ranga Dias on the College of Rochester in New York and Ashkan Salamat on the College of Nevada, Las Vegas (UNLV). Nature withdrew a separate paper final 12 months2 and Bodily Overview Letters retracted one this August3. It spells extra hassle specifically for Dias, whom some researchers allege plagiarized portions of his PhD thesis. Dias has objected to the primary two retractions and never responded concerning the most recent. Salamat accepted the 2 this 12 months.
“It’s at this level hardly stunning that the group of Dias and Salamat has a 3rd high-profile paper being retracted,” says Paul Canfield, a physicist at Iowa State College in Ames and at Ames Nationwide Laboratory. Many physicists had seen the Nature retraction as inevitable after the opposite two — and particularly since The Wall Street Journal and Science reported in September that 8 of the 11 authors of the paper — together with Salamat — had requested it in a letter to the journal.
Dias and Salamat didn’t reply to a request for remark by Nature’s information group. The retraction states that he and two different co-authors — Nugzari Khalvashi-Sutter and Sasanka Munasinghe, each at Rochester — “haven’t said whether or not they agree or disagree with this retraction”.
Early scepticism
This 12 months’s report by Dias and Salamat is the second important declare of superconductivity to crash and burn in 2023. In July, a separate group at a start-up firm in Seoul described4,5 a crystalline purple materials dubbed LK-99 — fabricated from copper, lead, phosphorus and oxygen — that they stated confirmed superconductivity at regular pressures and at temperatures as much as not less than 127 °C (400 kelvin). There was a lot on-line pleasure and lots of makes an attempt to breed the outcomes, however researchers rapidly reached a consensus that the fabric was not a superconductor at all.
LK-99 isn’t a superconductor — how science sleuths solved the mystery
Superconductors are vital in lots of functions, from magnetic resonance imaging machines to particle colliders, however their use has been restricted by the necessity to hold them at extraordinarily low temperatures. For many years, researchers have been growing new supplies with the dream of discovering one which reveals superconductivity with none refrigeration.
Specialists within the discipline have been sceptical since this 12 months’s Dias and Salamat paper was revealed, says Lilia Boeri, a physicist on the Sapienza College of Rome. This, she says, is partially due to controversies swirling across the group and partially as a result of the most recent paper was not written to what she considers a excessive customary.
“Just about each critical condensed-matter physicist I do know noticed immediately that there have been critical issues with the work,” says Peter Armitage, an experimental physicist at Johns Hopkins College in Baltimore, Maryland. Particularly, members of the group took problem with measurements of the fabric’s electrical resistance, saying it was not clear whether or not the property actually dropped to zero, or whether or not Dias and Salamat had subtracted a background sign from a key plot of resistance to create the looks that it did. Critics say that it shouldn’t be essential to take away background from this kind of measurement. In right now’s textual content, the journal said, “An investigation by the journal and post-publication overview have concluded that these issues are credible, substantial and stay unresolved.”
Stunning room-temperature-superconductor claim is retracted
Armitage provides that the publication of the paper additionally raises questions in regards to the editorial overview course of at Nature, and why reviewers didn’t catch the problems.
“The extremely certified knowledgeable reviewers we chosen raised a lot of questions in regards to the unique submission, which had been largely resolved in later revisions,“ says Karl Ziemelis, chief bodily sciences editor at Nature. “What the peer-review course of can’t detect is whether or not the paper as written precisely displays the analysis because it was undertaken.”
“Selections about what to simply accept for publication are usually not at all times simple to make,” Ziemelis continues. “And there could also be conflicts, however we try to take an unbiased place and to make sure the pursuits of the group at all times drive our deliberations.”
Audible clamour
Nature revealed the now-retracted paper on 8 March. That week, Dias himself introduced the outcomes to a standing-room-only viewers at a gathering of the American Bodily Society in Las Vegas. Over the audible clamour of the gang assembled exterior the room’s doorways — the place convention employees restricted entry to keep away from violating hearth laws — Dias briefly described a compound fabricated from hydrogen, lutetium and small quantities of nitrogen that was a superconductor at temperatures as much as 21 °C (294 kelvin) when saved at a stress of round 1 gigapascal (10,000 occasions atmospheric stress).
‘A very disturbing picture’: another retraction imminent for controversial physicist
Many groups had already created and experimented with related hydrogen-rich supplies, referred to as hydrides, after a milestone discovery in 2015. A bunch led by physicist Mikhail Eremets on the Max Planck Institute for Chemistry in Mainz, Germany, reported6 superconductivity in a hydrogen–sulfur compound at −70 °C (203 kelvin); on the time, this was a record-high working temperature for a superconductor. However Eremets’s materials required a a lot increased stress of 145 gigapascals (1.4 million occasions atmospheric stress) — corresponding to the crushing situations on the centre of Earth.
Since then, researchers have made hydride superconductors that push nearer and nearer to working at room temperature, however all of them work solely underneath excessive pressures. When Dias and Salamat revealed their paper in Nature in March, they seemed to have made a significant step in direction of a fabric that might discover sensible functions.
However some specialists had been already cautious due to the first Nature retraction. And a few say they instantly discovered the contemporary claims to be unbelievable. For example, the fabric described within the paper was presupposed to have round three hydrogen atoms for each lutetium atom. But when so, the lutetium would are inclined to donate an electron to every hydrogen, leading to a sort of salt, says Artem Oganov, a supplies scientist on the Skolkovo Institute of Science and Know-how in Moscow. “You get both an insulator or an especially poor metallic,” he says — not a superconductor.
One lab says it has partially reproduced Dias and Salamat’s outcomes utilizing a pattern offered by the Rochester group7. However many others, which tried creating their very own samples and operating assessments, couldn’t. And within the meantime, different causes for concern have arisen. An investigation launched by Bodily Overview Letters earlier than it retracted its paper by Dias and Salamat discovered “obvious knowledge fabrication”, as Nature’s news team reported in July. And an investigation launched by Nature’s journals group after it acquired an nameless critique of knowledge on this 12 months’s paper discovered that “the credibility of the revealed outcomes are in query”, based on September’s news story in Science.
Credibility issues
Armitage doesn’t suppose that Dias and Salamat will be capable to hold doing analysis, pointing to the investigation findings and allegations of plagiarism in Dias’s PhD thesis. The College of Rochester has confirmed to Nature that it has launched an investigation into the integrity of Dias’s work, which is being carried out now by exterior consultants. The college’s spokesperson didn’t reply questions on whether or not the establishment has but disciplined Dias. UNLV didn’t reply Nature’s queries about whether or not Salamat is being investigated, saying that “UNLV doesn’t publicly focus on personnel issues”, however that it “is dedicated to sustaining the best requirements for analysis integrity campus broad”.
How would room-temperature superconductors change science?
Canfield says that the Dias–Salamat collaboration has unfold a “foul vapour” over the sphere, which “is scaring younger researchers and funding companies away”.
“I’ve some colleagues who merely are afraid that this case of Dias places a shadow of doubt on the credibility of our discipline usually,” Eremets says.
Ho-Kwang Mao, director of the Middle for Excessive Strain Science and Know-how Superior Analysis in Beijing, is extra sanguine. “I don’t suppose it would have an effect on the funding for superconductivity analysis apart from extra cautious opinions, which isn’t essentially unhealthy,” he says.
Hai-Hu Wen, director of the Middle for Superconducting Physics and Supplies at Nanjing College in China, agrees. “Really, it appears less difficult to get funding for the analysis of superconductivity since some authorities officers appear to be influenced by the expectation of a room-temperature superconductor,” he says.
However Boeri says she has heard researchers complain that the controversies — the allegations of PhD thesis plagiarism and the findings of obvious knowledge fabrication — have made it tougher to recruit college students to work on superconductors. “We face a critical communication drawback, to make folks perceive that the sphere is wholesome — that though there could also be some unhealthy apples, the group’s requirements are a lot increased,” she says.
“Critical folks proceed to do wonderful and attention-grabbing work,” Armitage says. “Positive, they are often disheartened by this nonsense, but it surely gained’t cease the science.”