Towards Continuous Entanglement Distribution Between Two Quantum Network Nodes Using Neutral Atom Arrays and Fiber Cavities

Fast and efficient entanglement distribution between distant quantum nodes is essential for numerous emerging applications, such as large-scale fault-tolerant quantum computing using separate modules with photonic interconnects, multi-partite entanglement distribution from a central factory node, and distributed quantum sensing. Neutral atom arrays interfaced with optical cavities are a powerful platform to implement these capabilities. Nevertheless, such nodes require a large number of resources (atoms) to operate efficiently. 

Here we utilize an architecture in which atoms are continuously prepared, resulting in a large qubit flux, which is distributed between a networking and a computational zone. Our architecture uses fiber Fabry-Perot cavities (FFPC), which, with their small physical footprint, large cavity outcoupling rates, some of the highest cooperativies, and all-in-fiber operation are excellent candidates for large-scale remote entanglement distribution. Our experiment will use two FFPCs in the same glass cell, allowing for several topologies of operation.

We design an ultra-high vacuum system, which is sectioned into a cold atom source (a magneto-optical trap (MOT)) and a glass cell via a gate valve. Atoms from the MOT are transported via a running-wave optical lattice to the glass cell, which serves as the science region to establish high-fidelity quantum channels by time-multiplexing remote entanglement attempts. We will use a time-bin photonic encoding scheme on the Rb 87 D-lines, which is insensitive to polarization drifts and birefringence. This experimental setup will result in a continuous and efficient stream of remotely entangled states, which not only showcases multiplexed entanglement generation rates, but will also be able to generate a larger class of entangled photonic states using atomic entanglement.