aiqbench analysis
This paper proposes a protocol for implementing multi-qubit fan-out (C^n) gates across spatially separated parties using a pre-shared GHZ state, local CNOTs, and feed-forward operations. Its claimed gains are fewer CNOT and Hadamard gates and higher success probabilities than decomposition-based methods, with two optical architectures for heralded and post-selected photonic implementations. These are theoretical results, so experimental feasibility remains to be shown, but the work addresses a real bottleneck for distributed quantum computing.
Scalable long-distance quantum fan-out gates with reduced resource overhead
arXiv:2610.18049v1 Announce Type: new Abstract: Scalable long-distance quantum gates are essential for distributed quantum computation and scalable quantum networks. We propose an efficient scheme for implementing an $n$-qubit fan-out gate $C^n$ (also known as a controlled-NOT-$\cdots$-NOT gate) across spatially separated parties. Our protocol requires only a pre-shared $n$-qubit Greenberger-Horne-Zeilinger state, $n$ local controlled-NOT (CNOT) gates, and feed-forward operations, thereby reducing both the CNOT and Hadamard gate counts by $(n-2)$ when compared with the standard decomposition-based approach. We further develop two optical architectures to implement the heralded and post-selected $n$-photon fan-out gates, respectively. These schemes require fewer single photons resources and achieve higher success probabilities than their decomposition-based counterparts, representing significant improvements. The results indicate that our approach is experimentally feasible and pave the way toward practical long-distance quantum computation.
Abstract:Scalable long-distance quantum gates are essential for distributed quantum computation and scalable quantum networks. We propose an efficient scheme for implementing an $n$-qubit fan-out gate $C^n$ (also known as a controlled-NOT-$\cdots$-NOT gate) across spatially separated parties. Our protocol requires only a pre-shared $n$-qubit Greenberger-Horne-Zeilinger state, $n$ local controlled-NOT (CNOT) gates, and feed-forward operations, thereby reducing both the CNOT and Hadamard gate counts by $(n-2)$ when compared with the standard decomposition-based approach. We further develop two optical architectures to implement the heralded and post-selected $n$-photon fan-out gates, respectively. These schemes require fewer single photons resources and achieve higher success probabilities than their decomposition-based counterparts, representing significant improvements. The results indicate that our approach is experimentally feasible and pave the way toward practical long-distance quantum computation.
arXiv:2610.18049 [quant-ph]
(or arXiv:2610.18049v1 [quant-ph] for this version)
https://doi.org/10.48550/arXiv.2610.18049 Focus to learn more arXiv-issued DOI via DataCite (pending registration)
https://doi.org/10.1088/1367-2630/aeaf0f Focus to learn more DOI(s) linking to related resources
arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.
Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.
Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.
Full text under the publisher's open licence · 225 words

