Quantum emission from hexagonal boron nitride monolayers

Single-photon emission at room temperature can be achieved with hexagonal boron nitride due to electron and hole confinement in vacancy-related defects. Artificial atomic systems in solids are widely considered the leading physical system for a variety of quantum technologies, including quantum communications, computing and metrology1,2. To date, however, room-temperature quantum emitters have only been observed in wide-bandgap semiconductors such as diamond3 and silicon carbide4, nanocrystal quantum dots5,6,7, and most recently in carbon nanotubes8. Single-photon emission from two-dimensional materials has been reported9,10,11,12, but only at cryogenic temperatures. Here, we demonstrate room-temperature, polarized and ultrabright single-photon emission from a colour centre in two-dimensional hexagonal boron nitride. Density functional theory calculations indicate that vacancy-related defects are a probable source of the emission. Our results demonstrate the unprecedented potential of van der Waals crystals for large-scale nanophotonics and quantum information processing.