Current integrated circuits rely on electrons as information carriers. In the future, photons, which transmit information in optical circuits, could also take on this task. The basic building blocks of such novel chips are quantum light sources, which are then connected to quantum optical waveguides and detectors. An international team led by Alexander Holleitner and Jonathan Finley, physicists at the Technical University of Munich (TUM), has now succeeded in producing such quantum light sources in atomically thin material layers and placing them with nanometer precision.
"This represents an important first step towards optical quantum computers," says Julian Klein, first author of the study. "For future applications, the light sources must be coupled to photonic circuits, such as waveguides, to enable light-based quantum calculations. The decisive factor here is precise and precisely controllable placement of the light sources. In conventional three-dimensional materials such as diamond or silicon, there are also active quantum light sources, but they cannot be placed there precisely enough.