Chinese scientists reveal mechanism of high-temperature superconductivity

Shenzhen (ANTARA) - A team of Chinese researchers has made a major advance in understanding high-temperature superconductivity, providing crucial experimental evidence that offers new insights into the underlying mechanism. The research, conducted by scientists from the University of Science and Technology of China (USTC) and the Southern University of Science and Technology (SUSTech), succeeded in observing a ‘nodeless superconducting gap’ and ‘electron-boson coupling’ in a nickel-oxide-based thin-film superconductor at high temperature for the first time. The findings were published online recently in the journal Science. According to Xue Qikun, an academic at the Chinese Academy of Sciences and a professor at SUSTech, the symmetry of the superconducting gap and the mechanism of Cooper pairing are two major issues in high-temperature superconductivity research. This symmetry determines whether the superconducting gap is uniform. In a superconductor, electrons must pair to conserve energy, a process measured by the ‘superconducting gap’. While conventional superconductors have a completely uniform gap without ‘nodal’ points (points where the gap is zero), copper-based superconductors are believed to have nodes in certain directions. By studying the newly developed nickel-based thin-film layer, the research team found that its superconducting gap did not possess nodes. This indicates that nickel-based superconductors and copper-based ones may operate under different physical rules. The researchers also uncovered how electrons can pair. Since electrons naturally repel each other, they typically require an ‘mediator’ to bind them. The team found a unique ‘fingerprint’ signal in the energy data, suggesting that the mediator boson may play a role as a bridge in facilitating pairing in nickel-based materials. Nickel-based superconductivity research has become one of the leading topics in the global scientific community, marked by extreme technical challenges in material preparation and instrument development. Before this discovery, the team had achieved a series of systematic advances in material synthesis and studies of electronic structure, including the development of atomically precise preparation techniques for complex oxides, which pave the way for this research. ‘This is an important step in quantum materials research,’ said Xue. ‘It reflects China’s deepening role in cutting-edge physics and its growing contribution to global efforts to understand high-temperature superconductivity.’