All-to-all connectivity of Rydberg-atom-based quantum processors with messenger qubits

Rydberg atom arrays are a front-running platform for quantum processors. A major challenge threatening the scalability of this platform is the limited qubit connectivity due to the finite range of interatomic interactions. We explore an approach to realize dynamical all-to-all connectivity with the use of moving "messenger" atomic qubits that couple distant "computational" qubits held in a static tweezer array. We detail and compare four specific architectures based on this concept, each presenting distinct advantages and challenges tied to the efficacy of techniques used to couple, move and measure atomic qubits. We demonstrate that, though technologically demanding, the messenger-qubit paradigm opens a promising avenue to a truly scalable quantum processor based on Rydberg atoms.