A team led by Milan Allan of Ludwig Maximilian University of Munich and Ingmar Swart of Utrecht University solved a decades-old mystery about high-temperature superconductivity. They used scanning tunneling microscopy to measure shot noise—the electrical crackle of current—from cuprate materials like BSCCO. The researchers found that the noise signal was much weaker than in conventional superconductors, indicating the presence of Cooper pairs.
This provides evidence that the pseudogap, a state where electrons appear to vanish above the superconducting transition, is caused by electron pairing rather than frozen structural patterns. By comparing noise levels to energy gaps where electrons go missing, the team showed that pairing creates additional noise when charges arrive together. The work, published in Science, required years of instrument development and demonstrated that persistent student effort combined with electronics craftsmanship was essential to detect the faint pairing signatures.
This breakthrough offers new insight into why cuprates superconduct at higher temperatures than conventional materials.
Source: Ars Technica · Summarized by HeadlinesBriefing