Nanophotonics Represent a Novel Approach to Quantum Technologies

(EurekaAlert) This world of the most minute particles – also known as quantum systems – makes possible a wide range of technological applications, in fields which include magnetic field sensing, information processing, secure communication or ultra-precise time keeping. The production of these microscopically small structures has progressed so far that they reach dimensions below the wavelength of light. In this way, it is possible to break down hitherto existent boundaries in optics and utilize the quantum properties of light. In other words, nanophotonics represent a novel approach to quantum technologies.
As individual photons move in the quantum regime, scientists describe the relevant light sources as quantum emitters that can be embedded in nanodiamonds, among others. These special diamonds are characterized by their very small particle size, which can range from just a few to several hundred nanometres. Researchers at the University of Münster have now succeeded for the first time in fully integrating nanodiamonds into nanophotonic circuits and at the same time addressing several of these nanodiamonds optically. In the process, green laser light is directed onto colour centres in the nanodiamonds, and the individual red photons generated there are emitted into a network of nano-scale optical components.
“Working with diamond-based quantum systems in nanophotonic circuits allows a new kind of accessibility, as we are no longer restricted by microscope set-ups,” says Doris Reiter. “Using the method we have presented, it will be possible in the future to simultaneously monitor and read out a large number of these quantum systems on one chip,” she adds. The researchers’ work creates the conditions for enabling further studies to be carried out in the field of quantum optics – studies in which nanophotonics can be used to change the photo-physical properties of the diamond emitters. In addition to this there are new application possibilities in the field of quantum technologies, which will benefit from the properties of integrated nanodiamonds – in the field of quantum sensing or quantum information processing, for example.