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Superconductivity hunt gets boost from China’s $220 million physics ‘playground’

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On the outskirts of Beijing sits a set of unassuming buildings marked ‘X’, for ‘extreme’. Inside the Synergetic Extreme Condition User Facility (SECUF), researchers from all over the world are pushing matter to its limits with extreme magnetic fields, pressures and temperatures, and examining it in new ways with extremely precise resolution in time.

One particularly tantalizing goal of many researchers using this $US220-million toolbox is to discover new superconductors, materials that conduct electricity without resistance. “This kind of combination of extreme conditions offers a very good chance for new discoveries,” says SECUF’s founding director Li Lu, a condensed-matter physicist at the Chinese Academy of Science’s Institute of Physics (IOP) in Beijing.

Understanding the mechanisms that underlie superconductivity is an important step in the global race to finding a material that exhibits this phenomenon at room temperature, instead of under frigid conditions. Such a discovery could open the door to faster computers and cut electricity consumption, among other benefits.

Under extreme conditions, matter exhibits properties that would otherwise remain hidden. For instance, when some ordinary-seeming materials are subjected to high pressures and extreme cold, they become superconductors. But measuring superconductivity can be finicky, because it can show up differently depending on the technique used, says Konstantin Kamenev, a physicist at the University of Edinburgh, UK, who specializes in extreme-conditions engineering and instrumentation. The ability to mix and match such conditions at a single facility allows researchers to characterize their samples more fully and efficiently than they could otherwise. “It’s like a one-stop shop,” says Jinguang Cheng, a condensed-matter physicist at the IOP.

Extreme toolbox

Since September last year, all 22 experimental stations at SECUF have moved to full operation after a one-year trial period. Tucked into a corner of one of SECUF’s brightly lit rooms, Cheng oversees a station that combines a cubic anvil cell — a device that squeezes materials under enormous pressure on six sides — with two superconducting magnets and helium-based cooling systems. The sample-torturing instrument can be used to measure a range of electronic properties and characteristics. Although conventional high-pressure tools, such as diamond anvils, can accommodate samples that are only the width of a human hair, SECUF’s cubic anvil cell can compress larger samples, making it easier to measure electronic properties in finer detail, says Cheng.

He says that he and his colleagues have, in this way, discovered a handful of superconductors, including a rare magnetic one1 and another based on manganese2.

Interior view of the Synergetic Extreme Condition User Facility showing the Ultra-low temperature high magnetic field quantum oscillation experimental station.

The quantum oscillation station combines two superconducting magnets with ultra-low temperatures. Credit: Institute of Physics, Chinese Academy of Sciences

Behind a yellow warning barrier at the other end of the room sits a powerful superconducting magnet. Rui Zhou, a condensed-matter physicist at the IOP, and his colleagues have set up a station that combines the magnet with ultra-low temperatures to perform nuclear magnetic resonance (NMR) measurements. The technique tracks the behaviour of atomic nuclei in high magnetic fields. It offers a way of peering into the mechanisms that underlie high-temperature superconductors — those that operate above −195.8 °C.

SECUF’s magnet produces a weaker field — just 26 tesla — than do those at other facilities, such as the record-holding 45 T hybrid magnet, which is partially superconducting, at the US National High Magnetic Field Laboratory (NHMFL) in Tallahassee, Florida, and the 37 T resistive magnet at France’s National Laboratory for Intense Magnetic Fields in Grenoble, which require a lot of power to run. But it can maintain a stable magnetic field for up to one month instead of a few days or hours, because it guzzles much less power, says Zhou. That makes it possible for researchers to conduct longer experiments on the same sample, he explains.

Interior view of the Synergetic Extreme Condition User Facility showing the cubic anvil cell station.

The cubic anvil cell is located on the back wall, with black and yellow hazard tape. It can accommodate much larger samples than other high-pressure devices.Credit: Institute of Physics, Chinese Academy of Sciences

Another magnet system is enabling other types of superconductivity research. Gang Li, a condensed-matter physicist at the IOP, heads a station that combines blisteringly cold temperatures with a 30 T superconducting magnet and a 20 T one to detect quantum oscillations — physical phenomena that are used to map the electronic ‘fingerprint’ of materials. Last July, Alexander Eaton, a condensed-matter physicist at the University of Cambridge, UK, and his colleagues spent two weeks using the station to unpick the electronic properties of an unusual superconductor called uranium ditelluride3. “It was the only place we could do the experiment we wanted to do,” says Eaton.

Mix and match

Other superconductivity researchers are using multiple tools at SECUF. Guanghan Cao, a condensed-matter physicist at Zhejiang University in Hangzhou, China, used the cubic anvil cell and NMR to probe an intriguing chromium-based material he had discovered by accident. Cao and his colleagues spotted hints of superconductivity when they subjected it to high pressures using the cubic anvil cell4. Over at the NMR station, the researchers were also able to catch a glimpse of the compound’s magnetic properties. The ability to measure the material in multiple ways in one location enabled the researchers to conduct a more in-depth study in less time. “That’s really convenient for us,” Cao says.

Superconductivity isn’t the only phenomena researchers are pursuing at SECUF. Some researchers are using ultrafast lasers to study the properties of semiconductors, whereas others are using a range of instruments to hunt down elusive quantum states of matter. The facility is open to domestic and international users alike, and all proposals are considered equally, says Cheng. But the process will be more selective for all researchers this year to give successful applicants more time at each station, he adds.

Although researchers from all over the world are using the facility, Ali Bangura, a condensed-matter physicist at the NHMFL, says that SECUF could give China an edge over other countries in the quest to achieve room-temperature superconductivity. By expanding the scope of measurements on offer in one location, SECUF “substantially increases the likelihood of groundbreaking discoveries”, says Bangura.

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How an unlikely friendship with Jung influenced Pauli’s physics

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Hello Nature readers, would you like to get this Briefing in your inbox free every day? Sign up here.

Animated sequence from a video showing mini-colon oncogenesis.

Researchers grew tumours inside a model of gut tissue created using mouse stem cells.Credit: Matthias P. Lutolf et al/Nature

“In the last ten years, people spent a lot of time to develop and understand how to make organoids,” says chemical biologist Shuibing Chen. “But this is the time now to think more about how to use” them. Two teams have created ‘organoid’ models of the brain and gut to do just that. Researchers grew mouse stem cells on a scaffold to create a 3D model of the gut and then triggered tumour growth to mimic colorectal cancer. Another study created a brain organoid using human stem cells to mimic neurons involved in a rare genetic disorder, for which there is no good animal model. The organoid allowed researchers to test a novel therapy for the disease.

Nature | 6 min read

References: Nature paper 1 & paper 2

Engineers have created a compact but accurate atomic clock that weighs only 26 kilograms and is 1,000 times more precise than similar portable devices. The clock was tested on a three-week voyage aboard a New Zealand Navy ship around the Hawaiian Islands and kept time to within 300-trillionths of a second over a day. The best ‘optical’ clocks are based on atoms, such as strontium, that emit radiation at visible frequencies — but they are the size of dining tables and operate best under lab conditions. This new optical clock uses iodine molecules and could improve field measurements, such as mapping Earth’s gravitational field.

Nature | 4 min read

Reference: Nature paper

As the political and military alliance NATO expands, its science interests are changing. Aside from defence projects, new priorities include studying how climate change and AI will affect defence and security; protecting underwater infrastructure; and what NATO calls ‘hybrid threats’, such as interference in elections and disinformation. But the role of science in building diplomatic bridges between NATO nations and Russia has been on ice since Russia’s invasion of Crimea in 2014.

Nature | 6 min read

DNA has been extracted from ancient graves in four cemeteries in Hungary that were once at the heart of a mysterious nomadic culture. “These people basically didn’t have a voice in history, and we are kind of looking into them this way — through their bodies,” says archaeogeneticist Zuzana Hofmanová. The Avars were nomadic people who migrated to eastern and central Europe from the late sixth century to the early ninth century. The researchers analyzed genomes from 424 individuals using computational techniques to connect distant family members through their shared DNA, including a nine-generation family tree. The data suggest that the Avars kept aspects of their cultural heritage from the Asian steppes, such as very strict rules against inbreeding.

Nature | 5 min read

Get the expert view from geneticist Lara Cassidy in the related Nature News & Views article (7 min read, Nature paywall)

Reference: Nature paper

An excavated grave showing two skeletons, one of a horse lying on its side next to a human skeleton

A late Avar-period male grave also containing a horse and horse harness. Credit: Sándor Hegedűs

Features & opinion

In a desperate attempt to keep its nation above rising seas and its economy thriving, the government of The Maldives — a group of islands where 80% of land is less than 1 metre above sea level — has started to hoover up sand, coral, and debris from the ocean floor and use it to form new land. But the controversial project could put at risk coral reefs and seagrass meadows. “Atolls are extremely vulnerable ecosystems,” says water-management specialist Bregje van Wesenbeeck. “Once you start to interfere with them, you’re sort of failing them.”

Nature | 14 min read and video (5 minute watch)

Adventures in Volcanoland reminds us that we should all keep careful watch on the world’s volcanoes,” writes reviewer and volcanologist Heather Handley. She enjoys an ‘enchanting’ tour of the world’s more notorious and active volcanoes offered by volcanologist Tamsin Mather in her wide-ranging and absorbing book. Understanding volcanoes requires dedication and a degree of risk-taking. The effort is worth it, Mather explains, to help volcanologists answer big questions about how eruptions have affected life on Earth, and how to plan and prepare for the next big eruption.

Nature | 5 min read

“It was as if the wind had blown in from the lunatic asylum,” wrote psychoanalyst Carl Jung, of physicist Wolfgang Pauli’s first visit. Scientist and writer Arthur I. Miller tells the tale of how the patient-analyst relationship between Jung and Pauli evolved into a friendship that deeply influenced Pauli’s work. “Pauli had always been fascinated by alchemy, magic and myth, all of which were central to Jung’s psychology,” writes Miller. “Privately, he attributed his work towards CPT [charge, parity, and time] symmetry to discussions and creativity sparked through his conversations with Jung.”

Nature Reviews Physics | 8 min read

QUOTE OF THE DAY

Two years ago, Javed Khan, former head of the UK children’s charity Barnardo’s, posed this question and then answered it. A Nature editorial agrees and says that the United Kingdom is correct to attempt to end the single largest preventable cause of illness and death, as was New Zealand before its government changed its mind. (4 min read)

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science mourns giant of particle physics

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Few scientists have enjoyed as much fame in recent years as British theoretical physicist Peter Higgs, the namesake of the boson that was discovered in 2012, who died on 8 April, aged 94.

It was 60 years ago when Higgs first suggested how an elementary particle of unusual properties could pervade the universe in the form of an invisible field, giving other elementary particles their masses. Several other physicists independently thought of this mechanism around the same time, including François Englert, now at the Free University of Brussels. The particle was a crucial element of the theoretical edifice that physicists were building in those years,which later became known as the standard model of particles and fields.

Two separate experiments at the Large Hadron Collider (LHC) near Geneva, Switzerland — ATLAS and the CMS — confirmed Higgs’ predictions when they announced the discovery of the Higgs boson half a century later. It was the last missing component of the standard model, and Higgs and Englert shared a Nobel Prize in 2013 for predicting its existence. Physicists at the LHC continue to learn about the properties of the Higgs boson, but some researchers say that only a dedicated collider that can produce the particle in copious amounts — dubbed a ‘Higgs factory’ — will enable them to gain a profound understanding of its role.

Inspiring figure

“Besides his outstanding contributions to particle physics, Peter was a very special person, an immensely inspiring figure for physicists around the world, a man of rare modesty, a great teacher and someone who explained physics in a very simple yet profound way,” said Fabiola Gianotti, director-general of CERN in an obituary posted on the organization’s website; Gianotti who announced the Higgs boson’s discovery to the world at CERN. “I am very saddened, and I will miss him sorely.”

Many physicists took to X, formerly Twitter, to pay tribute to Higgs and share their favourite memories of him. “RIP to Peter Higgs. The search for the Higgs boson was my primary focus for the first part of my career. He was a very humble man that contributed something immensely deep to our understanding of the universe,” posted Kyle Cranmer, physicist at the University of Wisconsin Madison and previously a senior member of the Higgs search team at the CMS.

I was fortunate to meet Peter Higgs in 2013 (days after the Nobel prize announcement). He was modest as he told a group of PhD students the history of the boson theory. Afterwards, I was very lucky to get my copy of the New York Times with the discovery signed by him,” said Clara Nellist, a physicist at the University of Amsterdam and a member of the ATLAS particle-discovery collaboration.

A career highlight was helping Peter into a cab after the Collider exhibition launch @sciencemuseum in 2013 with a carrier bag of special-edition beer marking his recent Nobel,” posted Harry Cliff, a physicist at the University of Cambridge, UK.

“He disliked the limelight but was comfortable with friends and colleagues,” Frank Close, a physicist at the University of Oxford, UK, and author of the book Elusive: How Peter Higgs Solved the Mystery of Mass (2022), said in a statement to the UK Science Media Centre. “His boson took 48 years to appear, and when the Nobel was announced, he had disappeared to his favourite sea food bar in Leith.”

An exciting journey

Higgs’ work continues to be of fundamental importance, said physicist Sinead Farrington at the University of Edinburgh. “We’re still on an exciting journey to figure out whether some further predictions are true, namely whether the Higgs boson interacts with itself in the predicted way, and whether it might decay to other beyond the Standard Model particles,” she told the Science Media Centre.

For physicist and science writer Matt Strassler, Higgs’ death represents ‘the end of an era’. “Higgs was a fortunate scientist: he lived to see his insight at age 30 turn up in experiments 50 years later,” he posted on X. “His role and influence in our understanding of the #universe will be remembered for millennia.”



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Do black holes explode? The 50-year-old puzzle that challenges quantum physics

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In hindsight, it seems prophetic that the title of a Nature paper published on 1 March 1974 ended with a question mark: “Black hole explosions?” Stephen Hawking’s landmark idea about what is now known as Hawking radiation1 has just turned 50. The more physicists have tried to test his theory over the past half-century, the more questions have been raised — with profound consequences for how we view the workings of reality.

In essence, what Hawking, who died six years ago today, found is that black holes should not be truly black, because they constantly radiate a tiny amount of heat. That conclusion came from basic principles of quantum physics, which imply that even empty space is a far-from-uneventful place. Instead, space is filled with roiling quantum fields in which pairs of ‘virtual’ particles incessantly pop out of nowhere and, under normal conditions, annihilate each other almost instantaneously.

However, at an event horizon, the spherical surface that defines the boundary of a black hole, something different happens. An event horizon represents a gravitational point of no return that can be crossed only inward, and Hawking realized that there two virtual particles can become separated. One of them falls into the black hole, while the other radiates away, carrying some of the energy with it. As a result, the black hole loses a tiny bit of mass and shrinks — and shines.

Unexpected ramifications

The power of Hawking’s 1974 paper lies in how it combined basic principles from the two pillars of modern physics. The first, Albert Einstein’s general theory of relativity — in which black holes manifest themselves — links gravity to the shape of space and time, and is typically relevant only at large scales. The second, quantum physics, tends to show up in microscopic situations. The two theories seem to be mathematically incompatible, and physicists have long struggled to find ways to reconcile them. Hawking showed that the event horizon of a black hole is a rare place where both theories must play a part, with calculable consequences.

And profoundly unsettling ones at that, as quickly became apparent. The random nature of Hawking radiation means that it carries no information whatsoever. As Hawking soon realized2, this means that black holes slowly erase any information about anything that falls in, both when the black hole originally forms and subsequently as it grows — in apparent contradiction to the laws of quantum mechanics, which say that information can never be destroyed. This conundrum became known as the black-hole information paradox.

It has since turned out that black holes should not be the only things that produce Hawking radiation. Any observer accelerating through space could, in principle, pick up similar radiation from empty space3. And other analogues of black-hole shine abound in nature. For example, physicists have shown that in a moving medium, sound waves trying to move upstream seem to behave just as Hawking predicted. Some researchers hope that these experiments could provide hints as to how to solve the paradox.

A scientific wager

In the 1990s, the black-hole information paradox became the subject of a celebrated bet. Hawking, together with Kip Thorne at the California Institute of Technology (Caltech) in Pasadena, proposed that quantum mechanics would ultimately need to be amended to take Hawking radiation into account. Another Caltech theoretical physicist, John Preskill, maintained that information would be found to somehow be preserved, and that quantum mechanics would be saved.

But in 1997, theoretical physicist Juan Maldacena, who is now at the Institute for Advanced Study in Princeton , New Jersey, came up with an idea that indicated Hawking and Thorne might be wrong4. His paper now has more than 24,000 citations, even more than the 7,000 or so times Hawking’s paper has been cited. Maldacena suggested that the Universe — including the black holes it contains — is a type of hologram, a higher-dimensional projection of events that occur on a flat surface. Everything that happens on the flat world can be described by pure quantum mechanics, and so preserves information.

Cosmologist Stephen Hawking reacts during a conversation on October 10, 1979 in Princeton, New Jersey.

Stephen Hawking worked on the black hole information paradox throughout his life.Credit: Santi Visalli/Getty

At face value, Maldacena’s theory doesn’t fully apply to the type of Universe that we inhabit. Moreover, it did not explain how information could escape destruction in a black hole — only that it should, somehow. “We don’t have a concrete grasp of the mechanism,” says Preskill. Physicists, including Hawking, have proposed countless escape mechanisms, none of which has been completely convincing, according to Preskill. “Here it is, 50 years after that great paper, and we’re still puzzled,” he says. (Maldacena’s ideas were enough to change Hawking’s mind, however, and he conceded the bet in 2004.)

A quantum conundrum

Attempts to solve the information paradox have grown into a thriving industry. One of the ideas that has gained traction is that each particle that falls into a black hole is linked to one that stays outside through quantum entanglement — the ability of objects to share a single quantum state even when far apart. This connection could manifest itself in the geometry of space-time as a ‘wormhole’ joining the inside of the event horizon with the outside.

Entanglement is also one of the crucial features that make quantum computers potentially more powerful than classical ones. Moreover, in the past decade, the link between black holes and information theory has become only stronger, as Preskill and others have investigated similarities between what happens in holographic projections and the types of error-correction algorithm developed for quantum computers. Error correction is a way of storing redundant information that enables a computer — whether classical or quantum — to restore corrupted bits of information. Some researchers see quantum computation theory as the key to solving Hawking’s paradox. When creating a black hole, the Universe could be similarly storing several versions of its information — some inside the event horizon, some outside — so that the destruction of the black hole does not erase any history.

But other researchers think that the full resolution of the information paradox might have to wait until another big problem is solved — that of reconciling gravity with quantum physics. Hawking continued working on the problem almost up until his death, but with no clear outcome.

As for the title of Hawking’s paper, seeing actual black-hole explosions is a possibility that astronomers take seriously. Large black holes act like very cold bodies, but smaller ones are hotter, which makes them shrink faster; and the particles they shed should become more and more energetic, reaching a culmination when the black hole disappears. Hawking showed that ‘ordinary’ stellar-mass black holes, which form when massive stars collapse in on themselves at the end of their lives, take many times longer than the age of the Universe to get to this point. But, in principle, black holes with a range of smaller masses could have formed from random fluctuations in the density of matter during the first moments after the Big Bang. If a primordial black hole of the right mass were to fizzle into non-existence somewhere near the Solar System, it could be picked up by neutrino and γ-ray observatories.

Astronomers have not seen any black holes explode so far, but they are still on the lookout5. Such an observation would have certainly earned Hawking the Nobel Prize that eluded him all his life. As it is, the questions produced by his simple, inquisitive paper title look set to nourish the intersection between cosmology and physics for a good few years yet.

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the inside story of deception in a rising star’s physics lab

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In 2020, Ranga Dias was an up-and-coming star of the physics world. A researcher at the University of Rochester in New York, Dias achieved widespread recognition for his claim to have discovered the first room-temperature superconductor, a material that conducts electricity without resistance at ambient temperatures. Dias published that finding in a landmark Nature paper1.

Nearly two years later, that paper was retracted. But not long after, Dias announced an even bigger result, also published in Nature: another room-temperature superconductor2. Unlike the previous material, the latest one supposedly worked at relatively modest pressures, raising the enticing possibility of applications such as superconducting magnets for medical imaging and powerful computer chips.

Most superconductors operate at extremely low temperatures, below 77 kelvin (−196 °C). So achieving superconductivity at room temperature (about 293 K, or 20 °C) would be a “remarkable phenomenon”, says Peter Armitage, a condensed-matter researcher at Johns Hopkins University in Baltimore, Maryland.

But Dias is now infamous for the scandal that surrounds his work. Nature has since retracted his second paper2 and many other research groups have tried and failed to replicate Dias’s superconductivity results. Some researchers say the debacle has caused serious harm. The scandal “has damaged careers of young scientists — either in the field, or thinking to go into the field”, says Paul Canfield, a physicist at Iowa State University in Ames.

Previous reporting by The Wall Street Journal, Science and Nature’s news team has documented allegations that Dias manipulated data, plagiarized substantial portions of his thesis and attempted to obstruct the investigation of another paper by fabricating data.

Three previous investigations into Dias’s superconductivity work by the University of Rochester did not find evidence of misconduct. But last summer, the university launched a fourth investigation, led by experts external to the university. In August 2023, Dias was stripped of his students and laboratories. That fourth investigation is now complete and, according to a university spokesperson, the external experts confirmed that there were “data reliability concerns” in Dias’s papers.

Now, Nature’s news team reveals new details about how the scandal unfolded.

The news team interviewed several of Dias’s former graduate students, who were co-authors of his superconductivity research. The individuals requested anonymity because they were concerned about the negative impact on their careers. Nature’s news team verified student claims with corroborating documents; where it could not do so, the news team relied on the fact that multiple, independent student accounts were in agreement.

The news team also obtained documents relevant to the acceptance of the two Nature papers and their subsequent retractions. (Nature’s news and journal teams are editorially independent.)

The investigation unearths fresh details about how Dias distorted the evidence for room-temperature superconductivity — and indicates that he concealed information from his students, manipulated them and shut them out of key steps in the research process. The investigation also reveals, for the first time, what happened during the peer-review process for Dias’s second Nature paper on superconductivity. Dias did not respond to multiple requests for comment.

Together, the evidence raises questions about why the problems in Dias’s lab did not prompt stronger action, and sooner, by his collaborators, by Nature’s journal team and by his university.

Zero resistance

Dias came to the University of Rochester in 2017, fresh from a postdoctoral fellowship at Harvard University in Cambridge, Massachusetts, where he worked under physicist Isaac Silvera. “He’s not only a very talented scientist, but he’s an honest person,” Silvera told Nature’s news team.

Once Dias settled at Rochester, he pursued high-temperature superconductivity. Three years earlier, the field had been electrified when researchers in Germany discovered superconductivity in a form of hydrogen sulfide with the formula H3S at 203 K (−70 °C) and at extremely high pressures3. This was a much higher temperature than any superconductor had achieved before, which gave researchers hope that room-temperature superconductivity could be around the corner.

Dias proposed that adding carbon to H3S might lead to superconductivity at even higher temperatures.

Ranga Dias, a professor of mechanical engineering and physics at University of Rochester whose team is doing superconductivity research, in 2023.

Ranga Dias at the University of Rochester, New York.Credit: Lauren Petracca/New York Times/Redux/eyevine

His former graduate students say they synthesized samples of carbon, sulfur and hydrogen (CSH), but did not take measurements of electrical resistance or magnetic susceptibility that showed superconductivity. When a superconducting material is cooled past a critical temperature, its electrical resistance drops sharply to zero, and the material displays a similarly sharp change in its magnetic properties, called the Meissner effect. Students say they did not observe these key signs of superconductivity in CSH.

Because of this, students say they were shocked when Dias sent them a manuscript on 21 July 2020 announcing the discovery of room-temperature superconductivity in CSH. E-mails seen by the news team show that the students had little time to review the manuscript: Dias sent out a draft at 5.13 p.m. and submitted the paper to Nature at 8.26 p.m. the same evening.

When the students asked Dias about the stunning new data, they say, he told them he had taken all the resistance and magnetic-susceptibility data before coming to Rochester. The news team obtained e-mails that show Dias had been making similar claims since 2014. In the e-mails, Dias says he has observed a sulfur-based superconductor with a temperature above 120 K — which is relatively high, but far from room temperature. The students recall that they felt odd about Dias’s explanation but did not suspect misconduct at the time. As relatively inexperienced graduate students, they say, they trusted their adviser.

During peer review, however, Dias’s claims about CSH met more resistance. Nature’s news team obtained the reports of all three referees who reviewed the manuscript. Two of the referees were concerned over a lack of information about the chemical structure of CSH. After three rounds of review, only one referee supported publication.

The news team showed five superconductivity specialists these reports. They shared some of the referees’ concerns but say it was not unreasonable for the Nature editors to have accepted the paper, given the strongly positive report from one referee and what was known at the time.

The paper was published on 14 October 2020 to fanfare. Dias and a co-author, Ashkan Salamat, a physicist at the University of Nevada, Las Vegas (UNLV), also announced their new venture: Unearthly Materials, a Rochester-based company established to develop superconductors that operate at ambient temperatures and pressures.

At the time, students say, they trusted Dias’s explanations of where the resistance and magnetic-susceptibility data came from. Now, however, they no longer believe the result, or Dias’s explanation for the data. “I don’t think any of the other data was collected,” one student says.

Matters arise

Soon after the CSH paper was published, Jorge Hirsch, a condensed-matter theorist at the University of California, San Diego, began pressing Dias to release the raw magnetic-susceptibility data, which were not included in the paper. More than a year later, Dias and Salamat finally made the raw data public.

In January 2022, Hirsch and Dirk van der Marel, a retired professor at the University of Geneva in Switzerland, posted an analysis of the raw data on the preprint server arXiv4. They reported that the data points were separated by suspiciously regular intervals — each exactly a multiple of 0.16555 nanovolts. Hirsch and van der Marel stated that this feature was evidence of data manipulation.

Laser spectroscopy is used to trigger chemical reactions in experiments with room-temperature superconductivity in a University of Rochester lab.

Dias’s team used laser spectroscopy to measure the pressure of samples in diamond anvil cells.Credit: Lauren Petracca/New York Times/Redux/eyevine

Dias and Salamat responded in an arXiv preprint, arguing that the voltage intervals were simply a result of a background subtraction5 (the preprint was subsequently withdrawn by arXiv administrators). In high-pressure experiments, the signal of a sample’s superconductivity — a drop in voltage — can be drowned out by background noise. Researchers sometimes subtract this background, but the CSH paper did not mention the technique.

Questions about the data prompted Nature’s journal team to look further. In response to the concerns from Hirsch and van der Marel, editors at Nature asked four new referees to participate in a post-publication review of the CSH paper, which, like most peer review, was confidential.

Now, Nature’s news team has obtained the reports, which show that two of the anonymous referees found no evidence of misconduct. But two other reviewers, whom the news team can identify as physicists Brad Ramshaw at Cornell University in Ithaca, New York, and James Hamlin at the University of Florida in Gainesville, found serious problems with the paper.

In particular, Hamlin found evidence that led him to conclude the raw data had been altered. Nature applied an editor’s note to the CSH paper on 15 February 2022, alerting readers to concerns about the data.

On 4 March 2022, Dias and Salamat sent a rebuttal to the referees, denying data manipulation. But the rebuttal, seen by the news team, does not provide an explanation for the issues that Hamlin and Ramshaw found in the raw magnetic-susceptibility data. “I don’t know of any reasonable way this could come about,” Ramshaw wrote in a 13 March e-mail to Nature’s manuscript team in response to the rebuttal. “The simplest conclusion would be that these data sets are all generated by hand and not actually measured.”

On 27 March 2022, Hamlin sent Nature’s journal team his response to the rebuttal, which proposed an explanation for the odd data: rather than deriving the published data from raw data, Dias had added noise to the published data to generate a set of ‘raw’ data.

To assess the evidence for data fabrication, Nature’s news team last month asked two superconductivity specialists to review the post-publication reports. They said that Hamlin’s analysis gives credence to claims of misconduct.

In July 2022, using a different analysis, van der Marel and Hirsch independently came to the same conclusion and posted their findings on arXiv as an update to their original preprint. In it, they state that the raw data must have been constructed from the published data6.

In light of these concerns, Nature started the process of retracting the CSH paper. On 11 August, Nature editors sent an e-mail to all the co-authors asking them whether they agreed to the retraction. Students who spoke to the news team say that they were surprised by this, because Dias had kept them out of the loop about the post-publication review process. They remained unaware of any of the referees’ findings, including that there was evidence for data fabrication.

Nature retracted the CSH paper on 26 September 2022, with a notice that states “issues undermine confidence in the published magnetic susceptibility data as a whole, and we are accordingly retracting the paper”. Karl Ziemelis, Nature’s chief applied and physical sciences editor, says the journal’s investigation ceased as soon as the editors lost confidence in the paper, which “did leave other technical concerns unresolved”.

The retraction does not state what Hamlin and Ramshaw found in the post-publication review process instigated by Nature: that the raw data were probably fabricated. Felicitas Heβelmann, a specialist in retractions at the Humboldt University of Berlin, says misconduct is difficult to prove, so journals often avoid laying blame on authors in retractions. “A lot of retractions use very vague language,” she says.

Publicly, Dias continued to insist that CSH was legitimate and that the retraction was simply down to an obscure technical disagreement.

As Nature journal editors were investigating the CSH paper, the University of Rochester conducted two investigations into Dias’s work; a separate one followed the retraction. One of the university’s inquiries was in response to an anonymous report, which included some of the evidence indicating possible data fabrication that surfaced during Nature’s post-publication review.

The university told Nature’s news team that the three investigations regarding the CSH study did not find evidence of misconduct.

A spokesperson for Nature says that the journal took the university’s conclusions into account during its deliberations, but still decided to retract the paper.

The lack of industry-wide standards for investigating misconduct leaves it unclear whether the responsibility to investigate lands more on journals or on institutions. Ziemelis says: “Allegations of possible misconduct are outside the remit of peer review and more appropriately investigated by the host institution.”

Heβelmann says the responsibility to investigate can “vary from case to case”, but that there is a trend of more journals investigating misconduct, regardless of institutional action.

Funding agencies can also investigate alleged misconduct. In this case, Dias has received funding from both the US National Science Foundation (NSF) and the Department of Energy (DoE). The DoE did not respond to questions from Nature’s news team about Dias’s grant. The NSF declined to say whether it is investigating Dias, but it noted that awards can be terminated and suspended in response to an investigation.

The students who spoke to Nature’s news team say that none of them were interviewed in the three investigations of the CSH work by the university, which they were not aware of at the time. “We were hoping someone would come talk to us,” one student says. “It never happened.”

A new claim

By the time the CSH paper came under scrutiny by Nature journal editors in early 2022, Dias’s graduate students were starting to grow concerned. In summer 2021, Dias had tasked them with investigating a compound of lutetium and hydrogen (LuH), which he thought might be a high-temperature superconductor.

They began testing commercially purchased samples of LuH and, before long, a student measured the resistance dropping to zero at a temperature of around 300 K (27 °C). Dias concluded the material was a room-temperature superconductor, even though there was extremely little evidence, several students told Nature. “Ranga was convinced,” one student says.

Physicist James Jeffrey Hamlin in his lab at the University of Florida in Gainesville, Florida in 2023.

Physicist James Hamlin raised concerns about data reported by the Rochester group.Credit: Zach Stovall for Nature

But the measurements were plagued by systematic errors, which students say they shared with Dias. “I was very, very concerned that one of the probes touching the sample was broken,” one student says. “We could be measuring something that looks like a superconducting drop, but be fooling ourselves.” Although students did see resistance drops in a few other samples, there was no consistency across samples, or even for repeated measurements of a single sample, they told Nature’s news team.

Students were also worried about the accuracy of other measurements. During elemental analysis of a sample, they detected trace amounts of nitrogen. Dias concluded that the samples included the element — and the resulting paper refers to nitrogen-doped lutetium hydride. But further analysis, performed after the paper was submitted, indicated that nitrogen was not incorporated into the LuH. “Ranga ignored what I was saying,” one student says.

Because they were not consulted on the CSH paper, the students say they wanted to make sure they were included in the process of writing the LuH paper. According to the students, Dias initially agreed to involve them. “Then, one day, he sends us an e-mail and says, ‘Here’s the paper. I’m gonna submit it,’” one student says.

E-mails seen by Nature’s news team corroborate the timeline. Dias sent out the first draft of the LuH paper in an e-mail at 2.09 a.m. on 25 April 2022. “Please send me your comments by 10.30 AM,” Dias wrote. “I am submitting it today.” The manuscript they received did not contain any figures, making it difficult to assess. The students convinced Dias to hold off on submitting until the next day, when they could discuss it in person.

One student was upset enough by the meeting that they wrote a memorandum of the events four days afterwards. The memo gives details of how students raised concerns and Dias dismissed them. Students worried that the draft was misleading, because it included a description of how to synthesize LuH; in reality, all the measurements were taken on commercially bought samples of LuH. “Ranga responded by pointing out that it was never explicitly mentioned that we synthesized the sample so technically he was not lying,” the student wrote.

The students say they also raised concerns about the pressure data reported in the draft. “None of those pressure points correspond to anything that we actually measured,” one student says. According to the memo, Dias dismissed their concerns by saying: “Pressure is a joke.”

Students say that Dias gave them an ultimatum: remove their names, or let him send the draft. Despite their worries, the students say they had no choice but to acquiesce. “I just remember being very intimidated,” one student says. The student says they regret not speaking up more to Dias. “But it’s scary at the time. What if I do and he makes the rest of my life miserable?”

Dias made some changes that the students requested, but ignored others; the submitted manuscript contained a description of a synthesis procedure that had not been used. He sent the LuH manuscript to Nature that evening.

Paper problems

After Nature published the LuH paper in March 2023, many scientists were critical of the journal’s decision, given the rumours of misconduct surrounding the retracted CSH paper. They wanted to know on what basis Nature had decided to accept it. (In the case of both papers, neither the peer-review reports nor the referees’ identities were revealed.) Nature’s news team obtained those reviews and can, for the first time, reveal what happened during the review process for the LuH paper. Nature editors received the manuscript in April 2022 (about a month after Nature received the CSH post-publication review reports) and sent it out to four referees.

Brad Ramshaw giving a talk while using a projector.

Physicist Brad Ramshaw, together with James Hamlin, investigated data questions surrounding Dias’s superconductivity research.Credit: Kim Modic

All four referees agreed that the findings, if true, were highly significant. But they emphasized caution in accepting the manuscript, because of the extraordinary nature of the claims. Referee 4 wrote that the journal should be careful with such extraordinary claims to avoid another “Schön affair”, referring to the extensive data fabrication by German physicist Jan Hendrik Schön, which has become a cautionary tale in physics and led to dozens of papers being retracted, seven of them in Nature. Referees 2 and 3 also expressed concern about the results because of the CSH paper, which at the time bore an editor’s note of concern but had not yet been retracted. Referees raised a plethora of issues, from a lack of details about the synthesis procedure to unexplainable features in the data.

Although Dias and Salamat managed to assuage some of those concerns, referees said the authors’ responses were “not satisfactory” and the manuscript went through five stages of review. In the end, only one referee said there was solid proof of superconductivity, and another gave qualified support for publication. The other two referees did not voice support for publication, and one of them remained unsatisfied with the authors’ responses and wanted more measurements taken.

The news team asked five superconductivity specialists to review key information available to Nature journal editors when they were considering the LuH manuscript: the referee reports for the LuH paper and the reports indicating data fabrication in the CSH paper. All five said the documents raised serious questions about the validity of the LuH results and the integrity of the data.

“The second paper — from my understanding of timelines — was being considered after the Nature editors and a lot of the condensed-matter community were aware there were profound problems” with the CSH paper, Canfield says. The specialists also pointed to negative comments from some of the LuH referees, such as the observation by Referee 1 that “raw data does not look like a feature corresponding to superconducting transition”.

When asked why Nature considered Dias’s LuH paper after being warned of potential misconduct on the previous paper, Magdalena Skipper, Nature’s editor-in-chief, said: “Our editorial policy considers every submission in its own right.” The rationale, Skipper explains, is that decisions should be made on the basis of the scientific quality, not who the authors are.

Many other journals have similar policies, and guidelines from the Committee on Publication Ethics state that peer reviewers should “not allow their reviews to be influenced by the origins of a manuscript”. But not all journals say they treat submissions independently. Van der Marel, who is the editor-in-chief of Physica C, says that he would consider past allegations of misconduct if he were assessing a new paper by the same author. “If you have good reasons to doubt the credibility of authors, you are not obliged to publish,” he says.

Under review

Soon after the LuH paper was published in March 2023, it came under further scrutiny. Several teams of researchers independently attempted to replicate the results. One group, using samples from Dias’s lab, reported electrical resistance measurements that it said indicated high-temperature superconductivity7. But numerous other replication attempts found no evidence of room-temperature superconductivity in the compound.

As previously reported in Science, Hamlin and Ramshaw sent Nature a formal letter of concern in May. Dias and Salamat responded to the issues later that month, but the students say they were not included in the response, and learnt about the concerns much later.

A recording of a 6 July 2023 meeting between Dias and his students, obtained by Nature’s news team, shows that Dias continued to manipulate the students. Throughout the hour-long meeting, Dias said he wanted to involve the students in deciding how the team would respond to concerns about the LuH paper. But he didn’t tell them that he and Salamat had already responded to the technical issues raised by Hamlin and Ramshaw.

A graduate student makes adjustments to a diamond anvil cell used for a superconductivity experiment in the University of Rochester lab.

One of Dias’s students adjusts a diamond anvil cell, which the team used in its experiments.Credit: Lauren Petracca/New York Times/Redux/eyevine

The recording also reveals how Dias tried to manipulate the Nature review, because he believed the process would turn against him once more. “We can pretend we’re going to cooperate and buy time for a month or so, and then gather some senior scientists from the community,” Dias says in the recording. Dias explains how he wants to use the credibility of senior scientists — or the University of Rochester — to pressure Nature and avert a retraction.

But Dias’s plans were thwarted. Later that month, the students received an e-mail from Nature’s editors that showed Dias and Salamat had, in fact, already responded to the concerns. The students realized that Dias had sent them a document with the dates removed, apparently to perpetuate the falsehood.

On 25 July 2023, the journal initiated a post-publication review and asked four new referees to assess the dispute. All of the referees agreed that there were serious problems with the data, and that Dias and Salamat did not “convincingly address” the issues raised by Hamlin and Ramshaw. A spokesperson for Nature says the journal communicated with University of Rochester representatives during the post-publication review.

Separately, Dias’s students were beginning to mobilize, re-examining the LuH data they were able to access. The students hadn’t done this before, because, they say, Dias produced almost all of the figures and plots in both of the Nature papers.

Several other researchers told the news team that the principal investigator does not typically produce all the plots. “That’s weird,” Canfield says.

The students say they were especially concerned about the magnetic susceptibility measurements — again, the raw data seemed to have been altered. Looking at the real raw data, one student says, the material does not look like a superconductor. But when Dias subtracted the background, the student says, that “basically flips that curve upside down and makes it look superconducting instead”.

They continued finding problems. For the resistance measurements, too, the alleged raw data didn’t match data actually taken in the lab. Instead, it had been tweaked to look neater. “Science can be really messy … some of these plots just look too good,” a student says.

Back to school

By this point, some students were deeply concerned about their careers. “My thesis is going to be full of fabricated data. How am I supposed to graduate in this lab?” one student says. “At that point, I was thinking of either taking a leave of absence, or of dropping out.”

During the summer, Dias began facing other issues. One of his papers in Physical Review Letters8 — unrelated to room-temperature superconductivity — was being retracted after the journal found convincing evidence of data fabrication. Around the same time, Dias was stripped of his students and the University of Rochester launched a fourth investigation — this time, the students say they were interviewed.

In late August, the students decided to request a retraction of the LuH paper and compiled their concerns about the data and Dias’s behaviour. Before they sent a letter to Nature, Dias apparently caught wind of it and sent the students a cease-and-desist notice, which the news team has seen. But, after consulting a university official who gave them the green light, the students sent their letter to Nature editors, precipitating the retraction process. Eight out of 11 authors, including Salamat, signed the letter and the LuH paper was retracted two months later, on 7 November.

According to multiple sources familiar with the company, Salamat left Unearthly Materials in 2023 and is under investigation at UNLV. He did not respond to multiple requests for comment, and a spokesperson for UNLV declined to comment publicly on personnel issues.

The scandal has also had an impact on Nature’s journal team. “This has been a deeply frustrating situation, and we understand the strength of feelings this has stirred within the community,” Ziemelis says. “We are looking at this case carefully to see what lessons can be learnt for the future.”

With the university’s investigation now complete, Dias remains at Rochester while a separate process for addressing “personnel actions” proceeds. He has no students, is not teaching any classes and has lost access to his lab, according to multiple sources. Dias’s prestigious NSF grant — which has US$333,283 left to pay out until 2026 — could also be in jeopardy if the NSF finds reason to terminate it.

Dias has not published any more papers about LuH, but on X (formerly Twitter), he occasionally posts updates about the material. In a 19 January tweet, Dias shared an image of data, which he said showed the Meissner effect — “definitive proof of superconductivity!”

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AI Video characters can now follow the laws of physics and more

AI Video characters can now follow laws of physics and more

The world of video production is undergoing a significant transformation, thanks to the advent of artificial intelligence (AI) in video generation. This shift is not just a fleeting glimpse into what the future might hold; it’s a dynamic change that’s happening right now, reshaping the way we create and experience movies and videos. With AI, filmmakers are gaining an unprecedented level of flexibility and creative control, which is altering the landscape of the industry.

Imagine a tool that can produce videos so realistic they seem to obey the laws of physics. Such a tool now exists in the form of OpenAI’s Sora, an advanced AI video generation technology. Its outputs are incredibly lifelike, a clear indicator of the strides AI technology has made. Another company, P Labs, is making its mark with a feature that allows AI-generated characters to speak with perfectly timed mouth movements, enhancing the realism of digital actors.

The ability to convey emotions through video is crucial, and Alibaba Group’s Emote Portrait Alive research has taken this to a new level. This technology can create expressive portrait videos that are synchronized with audio, achieving realistic lip-syncing and emotional expressions. As a result, AI-generated characters can now establish an emotional connection with viewers, which is vital for storytelling.

AI Video Generation Advancements

Personalized movie experiences are another area where AI is making an impact. Anamorph has developed scene reordering technology that can create different versions of a film for individual viewers. This was demonstrated with a film about the visual artist Brian Eno. Such technology suggests a future where movies can provide a unique viewing experience every time, increasing their value for audiences.

Here are some other articles you may find of interest on the subject of creating videos films and short animations using artificial intelligence :

The process of filmmaking itself is being redefined by Stability AI, in collaboration with Morph Studios, has introduced a platform that simplifies film production. It features a storyboard visual drag-and-drop builder, which streamlines the complex steps involved in creating a film. This innovation makes it easier for a broader range of creators to engage in filmmaking.

Morph Studios Stability AI drag-and-drop interface

Morph Studios Stability AI video clip creation

LTX Studio has launched a comprehensive video creation platform that is altering the way we think about movie production. With this platform, you can produce entire movies from simple text prompts. It includes music, dialogue, and sound effects, and it ensures consistency in character portrayal. This platform is a prime example of the extensive capabilities of AI in video creation.

AI animators are also pushing boundaries by using AI-generated video clips to remake classic films. A team is currently working on a new version of “Terminator 2,” which is expected to make its Hollywood debut soon. This project showcases the potential of AI to reinterpret and breathe new life into beloved stories.

The  Future of AI Video Creation

As we look ahead to 2024, the film industry is preparing for the introduction of more sophisticated AI technology that will continue to enhance the quality of AI-generated videos. Filmmaking is on the cusp of a major shift, with AI poised to offer personalized cinematic experiences that connect with audiences in ways we’ve never seen before. The potential of AI in video generation goes beyond just new tools; it’s about redefining the art of storytelling and the magic of cinema.

This new era in filmmaking is not just about the technology itself but about the possibilities it unlocks. AI is enabling creators to explore new narratives, experiment with different storytelling techniques, and engage with their audiences on a deeper level. As AI continues to evolve, we can expect to see more innovative applications in video production that will challenge our traditional notions of what’s possible in film and video content.

The implications of AI in video generation extend to various aspects of the industry, from the way we write scripts to the way we edit and produce films. It’s an exciting time for filmmakers, actors, and audiences alike, as the lines between reality and AI-generated content become increasingly blurred. The advancements in AI video generation are not just about creating content faster or more efficiently; they’re about expanding the creative horizons of filmmakers and offering viewers new and immersive experiences.

As we embrace this new technology, it’s important to consider the ethical implications and the impact it will have on the industry. Questions about authenticity, creativity, and the role of human actors in a world of AI-generated characters are becoming more relevant. The industry must navigate these challenges thoughtfully to ensure that AI serves as a tool for enhancing the art of filmmaking rather than diminishing the value of human creativity.

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