Superconductors – Will the next world sensation come after ChatGPD?
7. August 2023Superconductors – Will the next world sensation come after ChatGPD?
HORST BUCHWALD
Part 2
Is LK-99 suitable for everyday use?
As ordered, as a continuation of this physics thriller, so to speak, Sukbae Lee and his team at the Quantum Energy Research Center in Seoul burst in with the claim that they had managed to produce a material they call LK-99 at room temperature and normal pressure shows all the characteristics of a superconductor.
But be careful. They are not the only ones who can show a material with this effect. The result:
– Lanthanum hybrid already loses its resistance at moderate cold or even just below room temperature. It already becomes superconducting at minus 23 degrees.
– Carbonaceous sulfur hydride performs even better – it already becomes superconducting at minus 15 degrees.
But ‚both materials fail due to their suitability for everyday use – because they only achieve these values when they are exposed to pressure of more than a hundred million atmospheres.
It remains to be clarified whether one can congratulate Lee and his team? That would be premature, as the physics community has some serious objections.
I summarize:
– the Koreans have not yet published their results in any specialist journal, only in two preprints. Thus, there has not yet been any independent assessment. One of these two specialist articles is criticized by colleagues because the database is rudimentary at best and the language used is not very professional.
– the physicist Douglas Natelson Rice University, writes on Twitter/X that in the preprints published by Lee and team there is a graphic that is identical in both, but shows different units of size on the Y-axis. While one representation is still reasonably conceivable, the second shows unphysical values: „It would mean that the magnetic mass susceptibility of the material is 154 times that of a perfect superconductor,“ writes Natelson. This hardly inspires confidence in the work.
“We don’t know which numbers to believe in the two preprints. That’s pretty sloppy.“
– Other physicists are also skeptical: „The publications are not yet entirely convincing,“ says materials researcher Susannah Speller from the University of Oxford. “The data does show a sharp drop in resistance suggesting an abrupt phase transition at around 100 degrees. But whether this is really caused by the formation of a superconducting state is unclear.” Because, as the researcher explains, an anomaly in the specific heat capacity can also produce such a jump.
– There are further doubts about the magnetic levitation of the LK-99 material: „At first glance, the levitation looks impressive,“ writes solid state physicist Richard Green of the University of Maryland on Twitter/X. However, the partially levitated sample showed high diamagnetic magnetization even in the normal state. Diamagnetism is the ability to displace and deflect an external magnetic field. „Hence, this sample could also levitate simply because it’s diamagnetic,“ says Green.
If these questions are answered positively, this is the second world sensation this year after the appearance of ChatGPD. And this time there are no dangers, because the superconductors will help in the fight against the climate crisis and at the same time drastically change the lives of all people.