High-temperature superconductors can jump from being a dead insulator to a conductive metal almost instantaneously.
April 29, 2026
Original Paper
Persistent Fermi Pockets and Robust Electron Pairing in Lightly Doped CuO2 Planes of Cuprate Superconductors
arXiv · 2604.23162
The Takeaway
Physicists used to believe that the transition into a superconducting state was a gradual process as more charge was added. New observations show that tiny Fermi pockets of metallic behavior appear at doping levels much lower than expected. This means the material switches its fundamental nature with just a tiny nudge of electricity. Understanding this abrupt jump helps explain why some materials can conduct electricity with zero resistance at higher temperatures. This insight is a major step toward creating materials that can carry power across the world without any energy loss. It challenges the established understanding of how these superconductors actually emerge.
From the abstract
High temperature superconductivity in cuprate superconductors is generally considered to be generated from doping the Mott insulators. The fundamental nature of the doped parent compounds as well as the microscopic origin of electron pairing remain critical issues in understanding the emergence of superconductivity. Here, using high-resolution spatially-resolved laser angle-resolved photoemission spectroscopy, we investigate the intrinsic electronic structures of the CuO$_2$ planes in multilayer