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arXiv · 2311.18179

Experimental realization of universal high-dimensional quantum gates with ultra-high fidelity and efficiency

Zhe Meng·Wen-Qiang Liu·Bo-Wen Song·Xiao-Yun Wang·An-Ning Zhang·Zhang-Qi Yin
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Abstract

Qudit, a high-dimensional quantum system, provides a larger Hilbert space to process the quantum information and has shown remarkable advantages over the qubit counterparts. It is a great challenge to realize the high fidelity universal quantum gates with qudits. Here we theoretically propose and experimentally demonstrate a set of universal quantum gates for a single optical qudit with four dimensions (including the generalized Pauli $X_4$ gate, Pauli $Z_4$ gate, and all of their integer powers), which are encoded in the polarization-spatial degree of freedom without multiple unstable cascaded interferometers. Furthermore, we also realize the controlled-$X_4$ gate and all of its integer powers. We have achieved both the ultra-high average gate fidelity $99.73\%$ and efficiency $99.47\%$, which are above the the error threshold for fault-tolerant quantum computation. Our work paves a way for the large-scale high-dimensional fault-tolerant quantum computation with a polynomial resource cost.

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Zhe Meng, Wen-Qiang Liu, Bo-Wen Song, Xiao-Yun Wang, An-Ning Zhang, Zhang-Qi Yin. 2023-11-30. Experimental realization of universal high-dimensional quantum gates with ultra-high fidelity and efficiency. https://arxiv.org/abs/2311.18179

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