• Photonics Research
  • Vol. 10, Issue 7, 1533 (2022)
Meng Li1、2、†, Chu Li1、2、†, Yang Chen3, Lan-Tian Feng3, Linyu Yan1、2, Qian Zhang1、2, Jueming Bao1、2, Bi-Heng Liu3, Xi-Feng Ren3、6、*, Jianwei Wang1、2、4、5, Shufeng Wang1、2、4、5, Yunan Gao1、2、4、5, Xiaoyong Hu1、2、4、5, Qihuang Gong1、2、4、5, and Yan Li1、2、4、5、7、*
Author Affiliations
  • 1State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • 2Frontiers Science Center for Nano-Optoelectronics, Peking University, Beijing 100871, China
  • 3Key Laboratory of Quantum Information, CAS University of Science and Technology of China, Hefei 230026, China
  • 4Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
  • 5Peking University Yangtze Delta Institute of Optoelectronics, Nantong 226010, China
  • 6e-mail: renxf@ustc.edu.cn
  • 7e-mail: li@pku.edu.cn
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    DOI: 10.1364/PRJ.452539 Cite this Article
    Meng Li, Chu Li, Yang Chen, Lan-Tian Feng, Linyu Yan, Qian Zhang, Jueming Bao, Bi-Heng Liu, Xi-Feng Ren, Jianwei Wang, Shufeng Wang, Yunan Gao, Xiaoyong Hu, Qihuang Gong, Yan Li. On-chip path encoded photonic quantum Toffoli gate[J]. Photonics Research, 2022, 10(7): 1533 Copy Citation Text show less

    Abstract

    The quantum Toffoli gate is one of the most important three-qubit gates, but it is challenging to construct a chip according to the complicated traditional circuit. Using the optimized 3D configuration with an overpass waveguide to reduce the circuit complexity, we successfully fabricate an on-chip path encoded photonic quantum Toffoli gate enabled by the 3D capability of the femtosecond laser direct writing (FLDW) for the first time to our knowledge, whose truth-table fidelity is higher than 85.5%. Furthermore, a path encoded four-qubit controlled-controlled-controlled NOT gate is written to confirm the scalability of this resource-saving technique. This work paves the way for the FLDW of more complex and powerful photonic quantum computation chips.

    1. INTRODUCTION

    Nowadays, various physical systems aiming at universal quantum computation are developing toward increasing the number of controllable qubits and realizing large-scale quantum computation [18]. By virtue of the unique advantages of photons, such as fast traveling speed, long coherence time, simple single-qubit operation, and multiple degrees of freedom, the photonic system is considered as one of the most important and possible solutions [9]. Quantum logic gates are the building blocks of quantum circuits to construct universal quantum computers. Both destructive probabilistic two-qubit controlled-NOT (CNOT) gates [10,11] and non-destructive heralded CNOT gates [1215] as well as three-qubit Toffoli gates [1619] and Fredkin gates [20,21] based on bulk optical elements have been demonstrated.

    Meng Li, Chu Li, Yang Chen, Lan-Tian Feng, Linyu Yan, Qian Zhang, Jueming Bao, Bi-Heng Liu, Xi-Feng Ren, Jianwei Wang, Shufeng Wang, Yunan Gao, Xiaoyong Hu, Qihuang Gong, Yan Li. On-chip path encoded photonic quantum Toffoli gate[J]. Photonics Research, 2022, 10(7): 1533
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