A team led by Yale University recently made a major discovery that could change our understanding of superconductivity, the phenomenon in which certain materials allow electricity to pass through without any resistance.
Superconductivity: a key phenomenon for the future
The superconductivity is a fascinating phenomenon where certain materials leave pass electricity without any resistance when cooled to extremely low temperatures. This means that there is no loss of energy in the form of heat, allowing electricity to be transported much more efficiently. If this technology were more widely used, it could revolutionize fields as varied as computing, transportation and even energy storage.
However, despite the discoveries of recent decades, there remains a lot of mystery surrounding the precise mechanisms that allow certain materials to become superconductors. One of the most intriguing theories proposes that superconductivity may be linked to a phenomenon called electronic nematicity.
What is electronic nematicity?
The electronic nematicity is a special state of matter in which electrons choose a preferred direction of movement instead of moving symmetrically. To understand this, imagine electrons in a material at room temperature: they move equally in all directions. However, as the temperature drops, these electrons can rearrange themselves and begin to favor a particular direction of motion, a phenomenon called nematic fluctuation.
Researchers have long speculated that these fluctuations might play a crucial role in superconductivity, but until recently there has been a lack of strong experimental evidence to confirm this hypothesis.
The discovery of Yale researchers: a major breakthrough
This is where the Yale University team took a decisive step forward. Led by Professor Eduardo H. da Silva Neto, the team studied materials made of iron selenide mixed with sulfur. These materials are particularly interesting because they exhibit both electronic nematicity and superconductivity, but without the drawbacks of some other materials, such as magnetism, that complicate studies.
To observe this phenomenon on the atomic scale, the researchers used a scanning tunneling microscope (STM), a device capable of capturing extremely detailed images of moving electrons. By cooling these materials to temperatures below 500 millikelvins, the researchers managed to observe nematic fluctuations and were able to identify a superconducting space, a key indicator of superconductivity.
Why is this discovery so important?
This discovery is critical because it provides the strongest evidence yet for superconductivity linked to nematic fluctuations. This opens new avenues for research, as it confirms that electronic nematicity could play a central role in the understanding and optimization of superconductivity.
Additionally, this means that materials such as iron selenides mixed with sulfur could be used to develop more efficient technologies, including in the areas of quantum computing, high-speed transport and energy storage. . The lack of energy loss in these materials could transform entire industries.
However, the Yale researchers’ discovery does not mark the end of the story. Several questions still remain unanswered. For example, what happens when the sulfur content of materials is increased? Does superconductivity continue to manifest itself or does it disappear? And could other materials also exhibit this phenomenon of electronic nematicity and superconductivity?
The Yale team plans to continue their research to answer these questions and further explore the properties of iron and sulfur materials. The results obtained so far suggest that they have taken an important step in the quest for more efficient superconducting materials.
