Keeping the photon in the dark: A new method for full control of quantum dots

Excitons—bound pairs of electrons and an electron hole—are quasiparticles that can arise in solids. While so-called “bright” excitons emit light and are therefore accessible, dark excitons are optically inactive. As a result, they have a significantly longer lifetime—which makes them ideal for storing and controlling quantum states and using them for advanced methods to generate entanglement.