It is possible that it is too early to grieve the loss of the room-temperature superconductivity claims.
On September 26, 2009, the journal NatureA paper that described a material that appeared to be a problem was withdrawn to turn into a superconductor at a cozy 15° Celsius (SN: 10/14/20). Many people in the field were rattled by the notice. A new experiment was conducted just days after the retraction, and supports the claim of the world-record temperatures, according to an eyewitness and other familiar with the experiment.
Superconductors carry electricity with no resistance, which means they’re useful for efficiently transmitting energy. They could save enormous amounts of energy that’s wasted in conventional metal wires. They are currently being used to create powerful magnetic field for medical imaging and particle Physics experiments. But to work, superconducting materials generally must be cooled far below 0° C, and many to temperatures close to absolute zero, or -273° C.
Researchers announced that a 2020 sample would contain hydrogen, sulfur, and some carbon. Record-breaking temperatures made him a superconductorThe possibility of room-temperature superconducting was a dream that seemed near reality. One hitch was that the material had to be under enormous pressures, about 2.6 million times atmospheric pressures — roughly the pressure found in parts of Earth’s core. However, this discovery is hailed as a potential technological and scientific revolution.
The controversy surrounding the report has raged for two years. The controversy centers on how researchers processed data showing changes in susceptibility, a magnetic property that can be altered by researchers. Editors at Nature took the unusual step of retracting the paper despite the researchers’ objections. “We have now established that some key data processing steps … used a non-standard, user-defined procedure,” write the editors at NatureIn the retraction. “The details of the procedure were not specified in the paper and the validity of the background subtraction has subsequently been called into question.”
The new experiment isn’t a duplicate of the one reported in the retracted paper, but the researchers replicated a portion of their research that raised red flags in the scientific community.
Ranga Dias, a physicist at the University of Rochester who headed the research on the now-retracted paper, led the new measurements at Argonne National Laboratory’s Advanced Photon Source in Lemont, Ill. “We have been working on this experiment for almost six months, building and reconfirming the correct methodology,” Dias says. “I would say the data we obtained at Argonne is more compelling, not just comparable,” to the data in the retracted Nature paper.
“The experiment took place over two days, September 27 and 28,” says physicist Nilesh Salke of the University of Illinois Chicago, who was not affiliated with the original research. Salke’s role at Argonne involved probing a sample of the material in question with X-rays while it was exhibiting magnetic susceptibility associated with high-temperature superconductivity. “We saw the first susceptibility signal on September 27, consistent with the claims reported in the retracted Nature paper.”
Jorge Hirsch of University of California San Diego thinks that this latest twist won’t end the controversy over the original claim. Hirsch is one of the most vocal critics against the claim about superconductivity at room temperature.
“I didn’t know it would be retracted, but was hoping it would be retracted,” says Hirsch, who was not affiliated with either the original or new experiment. He claims he sought the raw data from an earlier study, which he received a refusal from the authors. This was one month after the publication. “The authors said, ‘No we cannot give you the data because our lawyers said that it would affect our patent rights.’”
Intervention starting at NatureHirsch was eventually able to get the numbers. He was disturbed by what he saw. Hirsch doubts that superconductivity at high temperatures is possible in these types of hydrogen-based materials, but he says he objected to the way the data were processed.
“There were real problems between the raw data and the published data,” Hirsch says. He believes that Nature’s retraction doesn’t go far enough. “It’s not that the data were not properly processed.” Along with physicist Dirk van der Marel of the University of Geneva, Hirsch Examines data-related problemsA paper published in the September 15th issue of International Journal of Modern Physics. “Our analysis proves mathematically that the raw data were not measured in the laboratory. They were fabricated.”
Dias and his colleagues insist that there was no impropriety in the data or analysis they used and are continuing to work on experiments such as the one at Argonne. This work is still subject to peer review. For now, Nature’s retraction bolsters existing doubts around room-temperature superconductivity.
“In the end, all of this has to be validated by different groups getting the answer,” Hirsch says.
