Physicists in Germany have broken the record for high-temperature superconductivity. The team has achieved a resistance-free electrical current at the highest temperature yet: 250 Kelvin (or-23 degrees Celsius -9.4 degrees Fahrenheit).
Closer to nearing room temperature
The work is coming closer to nearing room temperature which has the physicists very excited. The pioneering research was done with a material called lanthanum hydride, under about 170 gigapascals of pressure.
With this material, the team had already achieved superconductivity at 215 Kelvin (-58.15 C°, -72 F°) earlier this year.
"This leap, by 50 Kelvin, from the previous critical temperature record of 203 Kelvin, indicates the real possibility of achieving room-temperature superconductivity (that is at 293 to 298 Kelvins) in the near future at high pressures, and the perspective of conventional superconductivity at ambient pressure," the authors wrote in their paper.
The work was led by Mikhail Eremets, the same physicist at the Max Planck Institute for Chemistry who set the previous record for superconductivity in 2014. However, that record was set using hydrogen sulfide under 150 gigapascals of pressure.
The Meissner effect
But before you get too excited, it is important to note that the new material has not yet passed all three tests for superconductivity. The first, the characteristic drop in resistance as the temperature falls, and second, that involves replacing the elements in the sample with heavier isotopes, have both been passed.
But one experiment is still missing, and that is the third one called the Meissner effect. The Meissner effect refers to the fact that as the material passes below the critical temperature and transitions into superconductivity, it should expel any magnetic field.
The reason the team has not yet observed this phenomenon is that their sample is too small. With samples just a few micrometers across, the researchers have not yet been able to measure this directly.
But with such promise, you can count on the fact that physicists everywhere will be trying to replicate and test these results. We may just get proof of the Meissner effect soon.
Furthermore, the work is bound to inspire some other avenues to pursue such as the trial of yttrium superhydrides for superconductivity. Computational models suggest that these materials could superconduct at temperatures above 300 Kelvin, truly room temperature.
The study has been published in the journal Nature.