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arXiv · 2505.02702

Efficient and high-fidelity entanglement in cavity QED without high cooperativity

Sumit Goswami·Cheng-Hsuan Chien·Neil Sinclair·Brandon Grinkemeyer·Shayne Bennetts·Ying-Cheng Chen·Hsiang-Hua Jen
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Abstract

The so-called state-carving protocol generates high-fidelity entangled states at an atom-cavity interface without requiring high cavity cooperativity. However, this protocol is limited to 50\% efficiency, which restricts its applicability. We propose a simple modification to the state-carving protocol to achieve efficient entanglement generation, with unit probability in principle. Unlike previous two-photon schemes, ours employs only one photon which interacts with the atoms twice - avoiding separate photon detections which causes irrecoverable probability loss. We present a detailed description and performance evaluation of our protocol under non-ideal conditions. High fidelity of 0.999 can be achieved with cavity cooperativity of only 34. Efficient state-carving paves the way for large-scale entanglement generation at cavity-interfaces for modular quantum computing, quantum repeaters and creating arbitrary shaped atomic graph states, essential for one-way quantum computing.

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Sumit Goswami, Cheng-Hsuan Chien, Neil Sinclair, Brandon Grinkemeyer, Shayne Bennetts, Ying-Cheng Chen, Hsiang-Hua Jen. 2025-05-05. Efficient and high-fidelity entanglement in cavity QED without high cooperativity. https://doi.org/10.1103/n9wg-k6q9

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