In the last few years, our group demonstrated that quantum dot based single-photon sources offer the possibility to encode quantum information in a manifold of degrees of freedom of light (polarization, frequency, photon number [1]) and can also generate entangled photons [2,3].

We are now aiming at the implementation of quantum communications protocols based on quantum dot single photon sources. We explore the advantages provided by these sources compared to attenuated laser, demonstrating standard quantum key distribution protocols. Our future projects involve moving toward communication protocols harnessing the various encoding possibilities with both single and entangled photons.

References:

• [1] Loredo JC, et al. Generation of non-classical light in a photon-number superposition, Nature Photonics 13 (11), 803-808 (2019)
• [2] Wein S. et al, Photon-number entanglement generated by sequential excitation of a two-level atom Nature Photonics 16 (5), 374-379 (2022)
• [3] Coste N., et al, High-rate entanglement between a semiconductor spin and indistinguishable photons Nature Photonics 2023.