Towards integrated microwave-to-optical conversion by atoms on a superconducting chip

Abstract

The coherent conversion of microwave to optical signals is for now a missing hardware for long-distance quantum communication between superconducting quantum (sub)processors that could form the nodes of a future quantum network. Various architectures for quantum simulations and information processing are being currently explored with different TRL levels. Among these, circuits of superconducting qubits have already moved from the fundamental research environment to the R&D units of companies. Recent developments have shown extraordinary abilities for performing fast and high-fidelity quantum logic operations. Their limitations are short coherence times precluding long-term storage of quantum information, and the difficulty of coupling distant quantum registers using microwave photons that are (near)resonant with qubit transitions. There is thus a need for (i) a quantum memory compatible with superconducting qubits, and (ii) a microwave to optical transducer to demonstrate the complete communication protocol between distant sub-registers consisting of a moderate number of superconducting qubits. Cold alkaline atoms which have long coherence time and possess transitions both in the MW and optical domain could certainly help improve on these limitations. In this presentation, I will describe how an integrated atom chip compatible with superconducting quantum processors and optical communication networks will be realized within the newly funded MOCA consortium that received the support from the QuantERA ERA-NET Cofund. I will also specifically discuss a newly developed solution to transport atoms in the near field of surfaces were the atom-light coupling strength will be enhanced.Atomes Ultra-Froids piégés dans des Réseaux Optiques Nano-StructurésConversion micro-onde - optique intégrée sur puce à atomes supraconductric