Chinese scientists have reported a major breakthrough in nickel-based high-temperature superconductors, offering new insights into one of the most challenging problems in condensed matter physics, according to a study published in Nature on Wednesday.

The research, led by Xue Qikun's team at the Southern University of Science and Technology, in collaboration with scientists from the University of Science and Technology of China, successfully created two new nickel-based superconducting materials under ambient pressure.

Superconductivity refers to a state in which electrical resistance drops to zero, allowing current to flow without energy loss. High-temperature superconductors, which operate at relatively higher temperatures, are considered key to future applications in energy transmission, precision sensing and quantum computing.

Nickel-based materials have emerged as a promising third class of high-temperature superconductors, following copper- and iron-based systems. However, progress in this field has been limited by a fundamental challenge: the high oxidation state required for superconductivity is difficult to achieve under conditions that also allow stable material growth.

To address this, the team developed a technique known as strong oxidation atomic-layer epitaxy, enabling precise control of material growth at the atomic scale under extreme oxidation conditions. This approach allows scientists to design and assemble atomic structures layer by layer, creating high-quality nickel oxide films with tailored properties.

Using this method, the researchers increased the superconducting transition temperature of a previously known bilayer nickel-based material from 45 kelvin to 63 kelvin. They also engineered new artificial structures by designing specific atomic stacking sequences, two of which exhibited superconductivity at 50 kelvin and 46 kelvin under ambient pressure.

Beyond creating new materials, the team also identified key electronic features linked to superconductivity. By combining atomic-level structural control with angle-resolved photoemission spectroscopy, they found that superconducting samples share a distinct electronic band structure near the Fermi surface, providing experimental evidence for the underlying mechanism.

Researchers say the findings help establish a direct link between atomic structure, electronic properties and superconductivity, offering a new pathway for understanding high-temperature superconductivity.

Scientists believe that comparative studies of nickel-, copper- and iron-based superconductors could ultimately help solve the long-standing puzzle of high-temperature superconductivity, paving the way for advances in energy systems, information technology and quantum science.