Boson Sampling with 20 Input Photons and a 60-Mode Interferometer in a 1014-Dimensional Hilbert Space

• Published in: Physical review letters 2019-12, Vol.123 (25), p.1
• Main Authors: Wang, Hui, Qin, Jian, Ding, Xing, Chen, Ming-Cheng, Chen, Si, You, Xiang, He, Yu-Ming, Jiang, Xiao, You, L, Wang, Z, Schneider, C, Renema, Jelmer J, Höfling, Sven, Lu, Chao-Yang, Pan, Jian-Wei
• Format: Article
• Language: English
• Subjects: Confidence intervals; Experiments; Hilbert space; Photons; Quantum computing; Samplers; Sampling
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.123.250503

Quantum computing experiments are moving into a new realm of increasing size and complexity, with the short-term goal of demonstrating an advantage over classical computers. Boson sampling is a promising platform for such a goal; however, the number of detected single photons is up to five so far, limiting these small-scale implementations to a proof-of-principle stage. Here, we develop solid-state sources of highly efficient, pure, and indistinguishable single photons and 3D integration of ultralow-loss optical circuits. We perform experiments with 20 pure single photons fed into a 60-mode interferometer. In the output, we detect up to 14 photons and sample over Hilbert spaces with a size up to 3.7 × 1014, over 10 orders of magnitude larger than all previous experiments, which for the first time enters into a genuine sampling regime where it becomes impossible to exhaust all possible output combinations. The results are validated against distinguishable samplers and uniform samplers with a confidence level of 99.9%.