Researchers have made a groundbreaking discovery that could lead to the development of superconductors that operate at higher temperatures.

They have discovered electron pairing, a crucial feature of superconductivity, that occurs at temperatures previously considered too high for this phenomenon.

Surprisingly, this was observed in an antiferromagnetic insulator, a type of material where such behavior was least expected.

Although the material did not exhibit zero resistance, a key characteristic of superconductivity, this discovery opens up new possibilities for developing similar materials into superconductors that operate at higher temperatures.

The research team, which includes members of the SLAC National Accelerator Laboratory, Stanford University and other institutions, published its findings in the journal Science.

The dance of electrons

Over the last century, scientists have learned a lot about how superconductors work. They know that for a material to become superconducting, electrons must form in pairs. And these pairs must be coherent – their movements must be synchronized.

Ke-Jun Xu, a Stanford graduate student and co-author of the study, used an analogy to explain the phenomenon.

“The electron pairs tell us they are ready for superconductivity, but something is stopping them,” he said.

“If we find a new method to synchronize the pairs, we could potentially use it to build superconductors at higher temperatures.”

Conventional vs. unconventional superconductors

Conventional superconductors, which are well studied, operate at temperatures that are typically close to absolute zero.

In these materials, lattice vibrations cause electrons to come together in pairs and “dance” synchronously.

Unconventional superconductors, on the other hand, function at much higher temperatures.

It is thought that something other than lattice vibrations helps pair electrons in these materials. Although researchers do not know exactly what is behind this, fluctuating electron spins are the most promising candidate.

The current study

In the current study, the researchers focused on a family of cuprates that had not been studied in detail because their maximum superconducting temperature was relatively low compared to other cuprates.

Researchers used ultraviolet light to study the atomic structure of cuprate material samples. This process causes electrons to be emitted from the material.

When these electrons are in a paired state, it is a little more difficult to eject them, creating an “energy gap.”

This gap persisted up to 150 Kelvin, indicating that electron pairing occurs at significantly higher temperatures than in the zero-resistance state, which occurs at about 25 Kelvin.

The way forward

Although the cuprate investigated in the study may not be the material that achieves superconductivity at room temperature, the findings may open up new avenues.

“Our results open up a potentially lucrative new path forward. We plan to investigate this pairing gap in the future to develop superconductors using new methods,” concluded Zhi-Xun Shen, a Stanford professor who oversaw the research.

The researchers plan to further investigate this incoherent pairing state and find ways to manipulate these materials to potentially force these incoherent pairs to synchronize.

If successful, this could lead to the development of superconductors that operate at higher temperatures, revolutionizing modern technology.