For over a century, scientists have been fascinated by superconductors—special materials that allow electricity to flow through them without losing any energy.
These materials can even make trains float above tracks!
However, there’s a catch: superconductors only work at extremely cold temperatures.
When they get warmer, they lose their magical properties and become ordinary conductors or even insulators that don’t conduct electricity at all.
Researchers have been on a quest to find or create superconductors that can work at higher temperatures, perhaps even at room temperature.
Such a discovery could revolutionize technology, impacting everything from computers and phones to the power grid and transportation.
Superconductors are also key to developing quantum computers, which could vastly outperform today’s computers.
In a groundbreaking study, scientists have observed a crucial feature of superconductors—called electron pairing—happening at much higher temperatures than previously thought.
This finding was made in a material where it was least expected: an antiferromagnetic insulator, a type of material that usually doesn’t conduct electricity.
Although this material did not achieve zero resistance (the hallmark of superconductivity), this discovery hints at the possibility of engineering materials that might become superconductors at higher temperatures.
The research team, which includes scientists from SLAC National Accelerator Laboratory and Stanford University, published their findings in the journal Science.
“These electron pairs are indicating that they are ready to enter a superconducting state, but something is preventing them from doing so,” explained Ke-Jun Xu, a Stanford graduate student and co-author of the study. “If we can find a way to get these pairs in sync, we might be able to create higher temperature superconductors.”
The dance of electrons
Over the past 100 years, scientists have learned a lot about how superconductors work. One key insight is that for a material to become superconducting, electrons must pair up and move together in a synchronized way.
If the electrons are paired but not in sync, the material might remain an insulator.
In superconductors, you can think of the electrons like two shy people at a dance party. At first, they don’t want to dance.
But then a song they both like comes on, and they notice each other—they’ve paired but haven’t started dancing yet.
Then, when a new favorite song plays, they finally start dancing together, and everyone else at the party joins in. At this point, the party is in full swing, and the material enters a superconducting state.
In this new study, researchers observed electrons that had “locked eyes” but hadn’t yet started dancing—meaning they were paired but not yet in sync.
A surprising material
The material in question is part of a family called cuprates, which have been known to superconduct at higher temperatures than most other materials.
However, the specific cuprate studied here was not well understood because its maximum superconducting temperature is relatively low—about 25 Kelvin, much colder than room temperature.
To explore this cuprate, researchers used ultraviolet light to examine the material at the atomic level. They found that electron pairing happened at temperatures up to 150 Kelvin, much higher than expected. Surprisingly, the pairing was strongest in the most insulating samples.
While this particular cuprate might not lead to room-temperature superconductors, the study offers valuable clues.
“This could open up a new path for research,” said Zhi-Xun Shen, a professor at Stanford who supervised the study. “We plan to keep studying this pairing gap to help design new superconductors that could one day work at higher temperatures.”
This research offers exciting possibilities for the future of superconductors, bringing us closer to the dream of room-temperature superconductivity.
