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.