Expérimental et théorique
Optical photons are excellent carriers of quantum information, but their lack of mutual interactions is a major roadblock for quantum technologies. Our new setup enables such interactions by transiently injecting the photons into an intra-cavity cold atomic gas and converting them into strongly interacting Rydberg polaritons. The Rydberg-blockaded cloud then acts as an effective two-level superatom with an enhanced coupling to light. We can coherently manipulate its state, efficiently detect it, and observe state-dependent pi phase flips on the light reflected from the cavity as required for many quantum engineering tasks. Recently, we fully deterministically generated free-propagating states of light with negative Wigner functions. We are now expanding the capabilities of this platform towards the multi-superatom / multi-mode regime. A possible experimental M2 internship will consist in demonstrating a cavity-mediated entanglement between two superatoms, leading to a PhD project focused on deterministic multi-photon quantum logic and Wigner-negative light states generation. Another internship topic, more oriented towards theory and experimental design, will be to study the possibility to trap and control a single atom next to a superatom. The following experimental PhD thesis will aim at developing quantum interconnects between static and flying qubits, in a collaboration with the quantum tech company Pasqal.