Programming Insulator-to-Metallic Transport in Insulating Materials via Surface Single-Atom Engineering

Reconfigurable electronic states in insulating materials enable metal-like transport while preserving the intrinsic robustness and functional versatility of insulating hosts, thereby redefining materials beyond the conventional metal-insulator dichotomy. However, obtaining such states remains extremely challenging owing to strong electronic localization inherent in insulating materials. We demonstrate a universal surface single-atom engineering strategy for linear and deep programming of electronic transport in insulating oxides and nitrides, including SiO₂, Al₂O₃, and BN, by selectively inducing local symmetry breaking, effective bandgap compression, and impurity-band percolation. Consequently, this strategy continuously narrows the bandgap and ultimately yields metallic transport characteristics with anomalously minimal temperature dependence. Furthermore, we apply single-atom-anchored SiO₂, an intrinsically electromagnetic wave-transparent material, to shielding with a record-high effectiveness of 98.6% for an ultrathin 80 µm film that also maintains stable performance over a temperature range of 300-800 K. This counterintuitive performance defies the conventional paradigm, demonstrating that an intrinsically insulating material can achieve electromagnetic shielding comparable to state-of-the-art metals while avoiding the temperature-induced performance degradation of metallic shielding materials. Overall, we believe that this study establishes single-atom band engineering as a general strategy for programming electronic transport in insulating materials, with broad implications for advanced electronics and unconventional functionalities.