High‐Fidelity Qudit‐Encoded High‐Dimensional Photonic Toffoli Gate Through Imperfect Photon Scattering
Fang‐Fang Du, Xin‐Shan Du, Zhuoya Bai, Qiang Zhu · Advanced Quantum Technologies · 2025
Abstract Quantum computation in high‐dimensional (HD) spaces holds significant promise for advancing a broad range of applications within quantum information technology (QIT), leading to processing more complex information and executing a wider array of quantum operations. In this study, a measurement‐free auxiliary cavity‐atom system is exploited to construct a three‐qudit photonic Toffoli gate in a ‐dimensional space. In addition, the auxiliary system maintains its initial state after a series of operations, eliminating the need for measurement and facilitating effective interactions between different photons by leveraging its extended coherence time. A comprehensive analysis of its fidelity and efficiency is performed, yielding impressive results that demonstrate the superiority and flexibility of this proposed protocol. Furthermore, the HD Toffoli gate lays the groundwork for realizing HD quantum computation for photon systems and significantly improves the efficiency of QIT.