Optically Addressable Molecule Spins at 2D Surfaces-I

Optically addressable surface spins represent a long-sought goal in quantum sensing, offering a route to probe and control quantum phenomena at atomic scales. Here, we present a hybrid architecture in which pentacene spin molecules are anchored onto two-dimensional hexagonal boron nitride (hBN) and self-aligned with the underlying lattice. This configuration yields robust optically detected magnetic resonance (ODMR) signals from 4 K to room temperature. Hahn-echo measurements reveal spin coherence times exceeding T₂ > 3.5 μs, surpassing those of bulk pentacene crystals and all previously reported spin defects in hBN by over an order of magnitude. These results establish a new quantum sensing platform that combines optical addressability, structural self-assembly, and environmental stability, laying the foundation for chemically tunable quantum interfaces at van-der-Waals surfaces.