Séminaire de Martin Cordier sur les sources de photons uniques ou de paires de photons

Martin, ancien stagiaire à l’IEMN, est post-doctorant à l’Université de Berlin dans le groupe Fondamentals of Optics and Photonics.

Le mercredi 10 novembre à 10h30
Amphithéâtre de l’IEMN – Laboratoire central – Villeneuve d’Ascq

Single photon turnstile

Illustration of the photon turnstile effect. After interacting with the atoms, the input laser light (Poissonian distribution) is transformed into a stream of single photons.

Nonclassical states of light (single photons, entangled photon-pair, squeezing) are considered as one of the building block for the development of quantum technologies. The generation of quantum state of light typically requires a highly nonlinear medium that is strongly coupled to an optical mode. Recently, significant advances have been made in this direction by strongly coupling photons to quantum emitters (e.g. quantum dots, NV centers) and exploiting the inherently nonlinear response of the latter. Here, based on a recent proposal [1], we experimentally demonstrate a novel mechanism for generating stream of single photons and entangled single-photon pairs [2,3]. Our setup consists of an ensemble of cold atoms evanescently coupled to a nanofiber with near-resonant light. Using a quantum interference effect between the entangled-photon pairs emitted by the atomic ensemble and the transmitted laser light, we are able to modify the photon-statistics of the light from Poisonnian distribution to bunching (photon-pair source) and antibunching (single photon source). This new scheme may turn out transformational in quantum information science and offers fundamentally new approaches for realizing single photon sources that outperform sources based on single quantum emitters and can be implemented for any wavelength regime from microwave to X-ray.

[1] A. Prasad et al., Nature Photonics 1 (2020).
[2] S. Mahmoodian et al., Phys. Rev. X 10, 031011 (2020).
[3] M.Cordier et al. in preparation.