Single Photon Sources

Optical quantum technologies require sources of true photon sources. Their applications include quantum cryptography, fundamental quantum optics experiments, quantum computing, as well as metrology and sensing. A suitable process is the fluorescence of a single two-level quantum system, because the excitation and subsequent decay to the ground state takes a finite time. The emitter can therefore only emit a single photon.

We use defects in the 2D material hexagonal boron nitride as a quantum light emitting platform. These emitters have a high quantum efficiency and short excited-state lifetime at room temperature, which results in a high single photon luminosity. Moreover, the 2D crystal lattice leads to near-ideal outcoupling, as emitters in atomically thin materials are not surrounded by any high refractive index material. At the moment we are combining our emitters with optical systems, including microcavities and integrated waveguide circuits.