Beyond binary quantum communication with integrated photonics

Essowéréo Tchao, Rafael Salas‐Montiel

Rick Bevers, Tieme Walstra, Daniel Nascimento Duplat +13 more

Laurent Labonté, Adrien Bensemhoun, Dorian Oser +12 more

Integrated photonic platforms provide a powerful route toward scalable and stable quantum light sources. In this presentation, we explore how quantum correlations can be generated, distributed, and characterized in the frequency domain using integrated photonic frequency combs. Relying on Kerr nonlinear microresonators operated below and above threshold, we demonstrate the generation of discrete entangled photon pairs as well as bright multipartite quantum states involving many spectral modes. We show how frequency multiplexing enables both multi-user quantum communication and enhanced data rates, while remaining fully compatible with integrated photonic circuits. Beyond bipartite entanglement, we report direct signatures of genuine multipartite quantum correlations in bright frequency combs. These results highlight integrated photonics as a versatile and scalable platform for multimode quantum technologies in communication, sensing, and metrology.

Christophe Couteau

Joseph A. Dolphin, Taofiq K. Paraïso, Han Du +3 more

Using hybrid integration, we overcome usual limitations inherent to specific photonic integration materials and produce high performance quantum transceivers. We measure exceptionally low quantum bit error rates over high channel loss and demonstrate real-world chip-to-chip quantum secure communications over distances beyond the 200 km range.