A flexible and dynamic single-atom-based electromagnetic switch

Conventional electromagnetic materials are functionally limited, lack real-time switching, and require centimeter-scale dimension and mechanical properties, posing challenges in complex and extreme applications. Here, we report a single-atom-anchored two-dimensional material synthesized via the general thermal splitting of heavy 5p -series nanoparticles onto graphitic carbon nitride (g-C 3 N 4 ) nanosheets. We demonstrate that the incorporation of heavier single atoms induces strong electronic correlations in quantum phases, leading to anomalous electronic phenomena such as band flattening, inversion, and densely packed, continuous van Hove singularities—features that are challenging to conventional approaches. The electromagnetic transistor enables dynamically programmable control over electromagnetic signals, including selective transmission, absorption, and shielding. This functionality is achieved with ultra-low voltage operation (<1.0 V) and a highly miniaturized transistor thickness of ∼800 μm, nearly an order of magnitude smaller than conventional materials. Furthermore, this transistor maintains stable performance under mechanical deformation and across a broad temperature range (300–900 K), ensuring long-term reliability in extreme conditions.