基于单光子源的预示性无损量子纠缠门

Heralded Nondestructive Quantum Entangling Gate with Single-Photon Sources.

作者信息

Li Jin-Peng, Gu Xuemei, Qin Jian, Wu Dian, You Xiang, Wang Hui, Schneider Christian, Höfling Sven, Huo Yong-Heng, Lu Chao-Yang, Liu Nai-Le, Li Li, Pan Jian-Wei

机构信息

Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.

CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.

出版信息

Phys Rev Lett. 2021 Apr 9;126(14):140501. doi: 10.1103/PhysRevLett.126.140501.

DOI:10.1103/PhysRevLett.126.140501

PMID:33891463

Abstract

Heralded entangling quantum gates are an essential element for the implementation of large-scale optical quantum computation. Yet, the experimental demonstration of genuine heralded entangling gates with free-flying output photons in linear optical system, was hindered by the intrinsically probabilistic source and double-pair emission in parametric down-conversion. Here, by using an on-demand single-photon source based on a semiconductor quantum dot embedded in a micropillar cavity, we demonstrate a heralded controlled-NOT (CNOT) operation between two single photons for the first time. To characterize the performance of the CNOT gate, we estimate its average quantum gate fidelity of (87.8±1.2)%. As an application, we generated event-ready Bell states with a fidelity of (83.4±2.4)%. Our results are an important step towards the development of photon-photon quantum logic gates.

摘要

有 herald 辅助的纠缠量子门是实现大规模光学量子计算的关键要素。然而，在基于线性光学系统的具有自由飞行输出光子的真正 herald 辅助纠缠门的实验演示中，受限于参量下转换中固有的概率性光源和双对发射。在此，通过使用基于嵌入微柱腔中的半导体量子点的按需单光子源，我们首次展示了两个单光子之间的 herald 辅助控制非门（CNOT）操作。为了表征 CNOT 门的性能，我们估计其平均量子门保真度为(87.8±1.2)%。作为一项应用，我们生成了保真度为(83.4±2.4)%的事件就绪贝尔态。我们的结果是朝着光子 - 光子量子逻辑门发展迈出的重要一步。