Scientists make dark excitons 300,000x brighter for quantum tech

Scientists from City University of New York (CUNY) and the University of Texas at Austin have made a significant breakthrough by amplifying the light emission of dark excitons—normally invisible quantum light-matter states found in atomically thin semiconductors—by nearly 300,000 times. Using a nanoscale optical cavity composed of gold nanotubes and a single atomic layer of tungsten diselenide (WSe₂), the team made these elusive states not only visible but also controllable at the nanoscale. This advance holds promise for developing faster, smaller, and more energy-efficient quantum computing and photonic technologies due to dark excitons’ long lifetimes and low environmental interactions. Further, the researchers demonstrated precise tuning of dark excitons using electric and magnetic fields, enabling on-demand control of their emission without altering the semiconductor’s natural properties. This approach preserves the material’s integrity while achieving record-breaking light-matter coupling. The study also resolved a longstanding debate in nanophotonics by showing that