2023-08-10 02:10:46
The spectacular announcement fell in the heart of summer. Korean researchers have claimed to have made a superconducting material that works at room temperature, a holy grail of modern physics with potentially revolutionary applications. But scientists remain skeptical because these results are far from proven.
A hitherto unknown team of scientists from Seoul reported on an experiment with a new material dubbed LK-99, in a preprint not yet published in a scientific journal. They attached a fascinating video where we see a small cube made of copper, phosphate and lead, floating above a magnet.
Unrest in the scientific community
The announcement triggered an avalanche of reactions on social networks, with many amateurs seeing it as a revolutionary discovery worthy of the Nobel Prize. Since then, “large laboratories, particularly in China and India, have tried to reproduce the experiment, without success. On the theoretical aspect, several pre-publications have already been posted,” notes Javier Villegas, research director at the CNRS.
“Science has been activated and that’s normal,” said this physicist from the joint CNRS/Thales laboratory to AFP. Because if the discovery were proven, it would lead, according to him, to a technological revolution. A room-temperature superconductor “would totally change the situation”, agrees Brigitte Leridon, CNRS researcher at ESPCI in Paris (Higher School of Industrial Physics and Chemistry).
Discovered in 1911, superconducting materials make it possible to conduct electric current without any resistance and therefore without losses. Unlike conventional conductors, such as those in toasters for example, where part of the current is transformed into thermal energy, which wastes electrical energy.
Niche apps
Superconducting coils produce powerful magnetic fields used for MRI machines, the CERN particle accelerator, the prototype Japanese Maglev train that levitates above the rails… Reserved for niche applications, the technology cannot be develop on a larger scale because there is a major obstacle: it only works at extremely cold temperatures (around -250 degrees), which requires complex and expensive installations.
Superconductivity at room temperature has therefore “dreamed physicists for 120 years”, explains Julien Bobroff, professor at the University of Paris-Saclay and researcher in the solid state physics laboratory. “With its magnetic levitation effects, one can imagine levitating hospital furniture to avoid contact with bacteria on the ground, flying carpets in the corridors of the metro…”, lists Brigitte Leridon.
Often dashed hopes
The most important advance would concern the storage and transmission of electricity, given that currently between 10 and 15% of the energy produced is lost. Generalizing superconduction would allow considerable energy savings – like “removing one or two nuclear reactors in France”, adds the physicist.
Scientists nevertheless keep a cool head as their hopes have already been dashed. “It’s been 30 or 40 years that announcements arrive on superconductors freeing themselves from the cold, and have turned out to be false for the most part”, underlines Professor Bobroff.
Relay on social networks
American researchers from the University of Rochester recently reported, in the prestigious journal Nature, a superconducting material operating at 21 degrees, but only at high pressure. Their work was coldly received because the same journal had to withdraw a previous study by this same team.
If “LK-99” makes so much “buzz”, it is because the experience seems “easy to reproduce, even for an amateur”, analyzes Julien Bobroff. The rise of social networks immediately spread information, amplified by the power of the image. “This is the first time that such an announcement has been accompanied by a video, and many saw it as proof,” argues the physicist.
With a great deal of sadness, we now believe that the game is over. LK99 is NOT a superconductor, not even at room temperatures (or at very low temperatures). It is a very highly resistive poor quality material. Period. No point in fighting with the truth. Data have spoken.
— Condensed Matter Theory Center (@condensed_the) August 8, 2023
Except that this video is not “scientific proof”. “It is surely LK-99 which levitates, but those who know about it know that there are materials floating in the same way without being superconductors”, deciphers Professor Bobroff.
“Extraordinary claims require extraordinary evidence,” said Professor Toby Perring, scientist at the ISIS neutron and muon laboratory (UK). The results should at least be reproduced once. “We will see more clearly in a few weeks. Given the responsiveness of the community, I have high hopes,” concludes Javier Villegas.
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