Very-large-scale integrated quantum graph photonics

Jueming Bao, Zhaorong Fu, Tanumoy Pramanik, Jun Mao, Yulin Chi, Yingkang Cao, Chonghao Zhai, Yifei Mao, Tianxiang Dai, Xiaojiong Chen, Xinyu Jia, Leshi Zhao, Yun Zheng, Bo Tang, Zhihua Li, Jun Luo, Wenwu Wang, Yan Yang*, Yingying Peng, Dajian LiuDaoxin Dai*, Qiongyi He, Alif Laila Muthali, Leif K. Oxenløwe, Caterina Vigliar, Stefano Paesani, Huili Hou, Raffaele Santagati, Joshua W. Silverstone, Anthony Laing, Mark G. Thompson, Jeremy L. O’Brien, Yunhong Ding*, Qihuang Gong, Jianwei Wang*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

107 Downloads (Pure)


Graphs have provided an expressive mathematical tool to model quantum-mechanical devices and systems. In particular, it has been recently discovered that graph theory can be used to describe and design quantum components, devices, setups and systems, based on the two-dimensional lattice of parametric nonlinear optical crystals and linear optical circuits, different to the standard quantum photonic framework. Realizing such graph-theoretical quantum photonic hardware, however, remains extremely challenging experimentally using conventional technologies. Here we demonstrate a graph-theoretical programmable quantum photonic device in very-large-scale integrated nanophotonic circuits. The device monolithically integrates about 2,500 components, constructing a synthetic lattice of nonlinear photon-pair waveguide sources and linear optical waveguide circuits, and it is fabricated on an eight-inch silicon-on-insulator wafer by complementary metal–oxide–semiconductor processes. We reconfigure the quantum device to realize and process complex-weighted graphs with different topologies and to implement different tasks associated with the perfect matching property of graphs. As two non-trivial examples, we show the generation of genuine multipartite multidimensional quantum entanglement with different entanglement structures, and the measurement of probability distributions proportional to the modulus-squared hafnian (permanent) of the graph’s adjacency matrices. This work realizes a prototype of graph-theoretical quantum photonic devices manufactured by very-large-scale integration technologies, featuring arbitrary programmability, high architectural modularity and massive manufacturing scalability.

Original languageEnglish
JournalNature Photonics
Pages (from-to)573–581
Publication statusPublished - 2023


Dive into the research topics of 'Very-large-scale integrated quantum graph photonics'. Together they form a unique fingerprint.

Cite this