Multiplexed Entanglement of Multi-emitter Quantum Network Nodes
AI Breakdown
Get a structured breakdown of this paper — what it's about, the core idea, and key takeaways for the field.
Abstract
Quantum networks that distribute entanglement among remote nodes will unlock transformational technologies in quantum computing, communication, and sensing. However, state-of-the-art networks utilize only a single optically-addressed qubit per node; this constrains both the quantum communication bandwidth and memory resources, greatly impeding scalability. Solid-state platforms provide a valuable resource for multiplexed quantum networking where multiple spectrally-distinguishable qubits can be hosted in nano-scale volumes. Here we harness this resource by implementing a two-node network consisting of several rare-earth ions coupled to nanophotonic cavities. This is accomplished with a protocol that entangles distinguishable 171Yb ions through frequency-erasing photon detection combined with real-time quantum feedforward. This method is robust to slow optical frequency fluctuations occurring on timescales longer than a single entanglement attempt: a universal challenge amongst solid-state emitters. We demonstrate the enhanced functionality of these multi-emitter nodes in two ways. First, we mitigate bottlenecks to the entanglement distribution rate through multiplexed entanglement of two remote ion pairs. Secondly, we prepare multipartite W-states comprising three distinguishable ions as a resource for advanced quantum networking protocols. These results lay the groundwork for scalable quantum networking based on rare-earth ions.