A strange dance is unfolding in the shadows of superconducting materials. Researchers have just observed unexpected pairs of electrons within them.
The findings challenge what we thought we knew about the temperature required for superconductivity. A discovery that could change the game.
In a recent study, an international team detected the formation of electron pairs in a cuprate, a copper-based material, at temperatures much higher than previously thought. These electron pairs typically appear at very low temperatures, near absolute zero (below -400°F), whereas they appeared here at -189°F (-123°C).
Traditionally, superconductors need to be cooled to extreme temperatures to allow electrons to pair, enabling them to conduct electricity without resistance. However, cuprates behave in a different and surprising manner.
Researchers observed a phenomenon where the electrons seemed paired but not yet coordinated. This unprecedented finding was made in a cuprate sample exposed to ultraviolet light. In response, the electrons in the material demonstrated an unusual resistance to being ejected.
The coupled electrons in the cuprate appeared to be locked in a sort of "pause," forming pairs but not reaching the synchronized state necessary for superconductivity. The temperature at which this phenomenon was observed exceeded the usual required temperature by a significant margin.
Illustration of two electrons transitioning from an unsynchronized state to a synchronized state in a superconducting material.
Source: Greg Stewart/SLAC National Accelerator Laboratory
Professor Zhi-Xun Shen from Stanford University hopes these discoveries will lead to the design of superconducting materials operating at higher temperatures. According to him, it could be a first step toward even more significant advancements.
The research team plans to continue exploring how to manipulate this incoherent pairing phenomenon to synchronize these electron pairs. Such synchronization could indeed pave the way for creating more efficient superconductors.
If these materials become operational at more accessible temperatures, they could transform numerous sectors, from quantum computing to transportation. A scientific and technological revolution might be underway.
What is superconductivity?
Superconductivity is a phenomenon occurring in certain materials at very low temperatures, where they lose all electrical resistance. In superconductivity, electric current flows without any energy loss, unlike traditional conductors where energy is dissipated as heat.
Electrons in a superconductor form "Cooper pairs," moving in a synchronized manner through the material. This synchronization allows current to pass without encountering obstacles or friction. Generally, for this property to manifest, temperatures need to be close to absolute zero.
Author of the article: Cédric DEPOND