Dirección de investigación : Eleni DIAMANTI

Photonic Resources for the Implementation of Quantum Network Protocols

In this thesis, we developed a source of photonic quantum states which we use to demonstrate important cryptographic primitives, namely quantum weak coin flipping, and the certified transmission of quantum information through an untrusted and lossy quantum channel. Our source produces photon-pairs at telecom wavelengths, with high heralding efficiency and closeness to a maximally-entangled state. Pairs are used as heralded single-photons to perform the first implementation of a quantum weak coin flipping protocol, allowing two distant players to decide of a random winner. Using quantum resources allows to enforce information-theoretic security and cheat-sensitivity. Cheating players are detected in a verification step, which involves a carefully optimized linear optical interferometer including beam splitters with variable reflectivities and a fast optical switch. We demonstrate high values of our protocol benchmarks for attenuations corresponding to several kilometers of telecom optical fiber. Alternatively, photon-pairs are used as maximally-entangled qubits to certify the transmission of a single qubit through an untrusted and lossy quantum channel. We provide a whole new protocol, based on the already-known self-testing technique and new fundamental results on lossy quantum channels. We demonstrate that protocol using photon-pairs entangled in polarization to probe the channel. We show it allows the certification of quantum communication for a large amount of losses induced by the channel. Finally, we provide a novel design in order to adapt this source to multipartite entanglement generation, enabling the implementation of new protocols involving more than two players.

Publicaciones 2022-2023

• 2023
  • S. Neves, V. Yacoub, U. Chabaud, M. Bozzio, I. Kerenidis, E. Diamanti : “Experimental cheat-sensitive quantum weak coin flipping”, Nature Communications, vol. 14 (1), pp. 1855, (Nature Publishing Group) (2023)
  • S. Neves, L. Martins, V. Yacoub, P. Lefebvre, I. Šupić, D. Markham, E. Diamanti : “Experimental Certification of Quantum Transmission via Bell’s Theorem”, (2023)
• 2022
  • S. Neves : “Ressources Photoniques pour l’Implémentation de Protocoles de Réseaux Quantiques”, tesis, defensa 02/12/2022, dirección de investigación Diamanti, Eleni (2022)
  • S. Neves, V. Yacoub, U. Chabaud, M. Bozzio, I. Kerenidis, E. Diamanti : “Experimental cheat-sensitive quantum weak coin flipping”, (2022)
  • R. Yehia, S. Neves, E. Diamanti, I. Kerenidis : “Quantum City: simulation of a practical near-term metropolitan quantum network”, (2022)