Fast photon-mediated entanglement of continuously-cooled trapped ions for quantum networking

TL;DR

This paper demonstrates a high-fidelity, continuous entanglement of trapped ions using photon interference, with innovative cooling techniques enabling sustained quantum networking operations.

Contribution

It introduces a method for fast, photon-mediated entanglement of trapped ions with continuous cooling, improving quantum network scalability.

Findings

Achieved entanglement fidelity > 94%

Established a continuous entanglement rate of 250 per second

Implemented sympathetic cooling with ytterbium ions

Abstract

We entangle two co-trapped atomic barium ion qubits by collecting single visible photons from each ion through in-vacuo 0.8 NA objectives, interfering them through an integrated fiber-beamsplitter and detecting them in coincidence. This projects the qubits into an entangled Bell state with an observed fidelity lower bound of F > 94%. We also introduce an ytterbium ion for sympathetic cooling to remove the need for recooling interruptions and achieve a continuous entanglement rate of 250 1/s.