Year: 2026
Type: article
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- ⋯ -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.
Source: New Journal of Physics
Authors: Wen-Qiang Liu, Hai-Rui Wei
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,610
Awards: G6599687237, G7498805956
OpenAlex ID: W7215041727