Quantum mechanical single-gold-nanocluster electroluminescent light source at room temperature

The robust, nonclassical electroluminescence was analyzed at room temperature from spatially isolated Au nanoclusters within easily fabricated dc-generated nanoscale break junctions. It was found that the electrically contacted, spatially isolated gold nanoclusters exhibit clear photon antibunching in their strong, near-infrared electroluminescence. Simultaneous emission of two or more photons was forbidden for spatially isolated single quantum systems. The results demonstrated the single quantum nature of several-atom gold molecules and suggested their use as room-temperature electrically driven single-photon sources.