Atomic‐Scale Light Coupling Control in Ultrathin Photonic Membranes

ABSTRACT Atomic‐layer and 2D materials have emerged as essential building blocks for next‐generation quantum and semiconductor technologies, where atomic‐scale control over light‐matter interactions is critical. However, their inherently small interaction volume poses fundamental challenges for efficient integration into quantum and nanophotonic devices. Addressing this limitation requires the development of photonic platforms that can effectively enhance atomic‐scale optical coupling. To this end, freestanding nanomembranes with extreme thinness and minimal radiative loss offer an ideal framework for integrating these materials into photonic systems. Here, we demonstrate an ultrathin photonic nanomembrane enabling atomic‐scale control of light coupling. This architecture supports strong field confinement at the surface and significantly enhances light‐matter interaction. Through the integration of atomic‐layer dielectrics, we achieve Å‐level thickness modulation, where each deposition cycle leads to an ultrafine shift of the high‐Q resonance. High‐resolution spatial mapping further confirms uniform and deterministic resonance tuning across the nanomembrane surface. Furthermore, by integrating a WS 2 monolayer with the photonic nanomembrane, strong field localization within the monolayer and a significant emission enhancement are achieved. This approach offers a scalable and versatile route for atomic‐scale light coupling, helping to overcome the limitations of conventional photonics and opening opportunities in quantum photonics, optoelectronics, and advanced semiconductor technologies.