Context & Research

Semiconductor quantum dots (QD) have gained popularity as near-perfect photon sources in the last decade. Our group at the Center for Nanoscience and Nanotechnologies demonstrated that QD devices are capable to emit single photons with high purity, indistinguishability, and state-of-the-art brightness [1,2]. Additionally, QD photon emission rate is unparalleled by other technologies. QD thus are a serious contender to scale technologies like quantum computing and quantum communications to real-world applications [3].

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 [4]) and can also generate entangled photons [5,6].

In this project, the objective is to implement quantum communications protocols based on these promising single photon sources. The advantage provided by these sources compared to attenuated lasers will first be explored and demonstrated with standard quantum key distribution protocols, thus evidencing the assets of QD devices. In a second step, we will move toward communication protocols harnessing the various encoding possibilities with both single photons and entangled photons.

We are looking for bright and motivated PhD candidates with solid background in quantum optics, ready to embark on this experimental research line. The PhD is funded by both the Région Ile de France through the PRPHD program via the DIM QuanTiP and Quandela.

The project will benefit from collaborations with researchers and engineers in the vibrant, synergic environment in the joint laboratory between C2N and Quandela as well as within the regional and national collaborations within the QuantIP Paris QCI project and the QCom-TestBed PEPR project.

If you are interested contact us!

[1] Somaschi, N. et al. Near-optimal single-photon sources in the solid state. Nature Photonics 10, 340–345 (2016).
[2] Thomas S. et al, Bright Polarized Single-Photon Source Based on a Linear Dipole, Phys. Rev. Lett. 126, 233601 (2021).
[3] Maring N., et al. A general-purpose single-photon-based quantum computing platform, arXiv:2306.00874.
[4] Loredo JC, et al. Generation of non-classical light in a photon-number superposition, Nature Photonics 13 (11), 803-808 (2019).
[5] Wein S. et al, Photon-number entanglement generated by sequential excitation of a two-level atom Nature Photonics 16 (5), 374-379 (2022).
[6] Coste N., et al, High-rate entanglement between a semiconductor spin and indistinguishable photons Nature Photonics 2023.

Contacts:

Pascale Senellart (Pascale.senellart@univerisite-paris-saclay.fr)

Nadia Belabas (Nadia.belabas@universite-paris-saclay.fr)

Dario Fioretto (Dario.fioretto@universite-paris-saclay.fr)