Lidia Lozano Martín (ICCUB)

Is it possible to develop an efficient solid-state emitter of single and entangled photons suitable for space to ground communications among other quantum applications? Present single-photon and entangled-photons emitters exhibit important challenges, limiting their use in quantum applications like secure communication based on quantum key distribution (QKD), quantum metrology and sensing. Some of these challenges are directionality, efficiency or quantum coherence. It is also important to make them robust so they can be used in extreme environments, such as space, to allow their use for long distance networks. Our goal is to build an emitter using colloidal quantum dots (QDs) as the source of single and entangled photons – given their small size, the production of photons on demand and their wavelength tunability – enhanced by a resonant cavity to direct the photon emission in a particular direction, improve the quantum efficiency and provide higher stability. For this purpose, we are working on the development of an optical system for measuring single-photon emission produced by QDs, by means of a Hanbury Brown and Twiss (HBT) setup to observe antibunching behaviour. At the same time, we have started the fabrication of solid-state structures to enhance the emission of QDs for their future implementation. The present talk explains the first experimental steps taken to achieve our goal.