PhD student
Team : QI
Arrival date : 10/01/2020
    Sorbonne Université - LIP6
    Boîte courrier 169
    Couloir 25-26, Étage 1, Bureau 103
    4 place Jussieu
    75252 PARIS CEDEX 05

Tel: +33 1 44 27 70 29, Verena.Yacoub (at) nulllip6.fr
Experimental demonstration of quantum advantage for computing and communication tasks

The goal of the emerging quantum networks is to provide fundamentally new technology by enabling communication of quantum information between distant parties, eventually leading to a Quantum Internet. Such networks allow the transmission of quantum bits (qubits) over long distances in order to solve tasks that are provably impossible for any classical communication network. Possibly the most well-known protocol is quantum key distribution, which enables secure communication; but, quantum communication is also known to offer significant advantages for many other tasks. In this context, it is important to be able to rigorously demonstrate such an advantage for useful tasks with presently available or near-term technology. Photonic resources will be at the heart of the quantum network infrastructure as they provide the optimal means for communication between the network nodes. In this thesis project, we propose to use advanced photonic experimental techniques with the goal of demonstrating a quantum advantage in communication efficiency and computing time for tasks relevant for real-world applications. Prominent examples that we will consider are communication complexity tasks, such as fingerprinting and the estimation of the Euclidean distance of two data sets, and computing tasks like the verification of NP-complete problem solutions when limited information about the solution is available to the verifier. Our experiments will exploit the manipulation of trains of coherent light pulses and of entangled photon states, linear optic circuits and high-performance single-photon detection based on superconducting nanowires. To address the stringent constraints imposed by the theoretical analysis of the aforementioned protocols to show a quantum advantage with respect to classical resources, the experiments performed in the thesis will test new techniques for improving the efficiency and the quality of the generated quantum states and of the detection process. We will aim at surpassing the state of the art with respect to several benchmarks, both for our experimental resources and for the demonstrated applications. We expect that the outcome of this thesis will provide solid evidence of the power of quantum photonic technologies for the emerging quantum information networks