Quantum interference and quantum correlation, as two main features of quantum optics, play an essential role in quantum information applications, such as multi-particle quantum walk and boson sampling. While many experimental demonstrations have been done in one-dimensional waveguide arrays, it remains unexplored in higher dimensions due to tight requirement of manipulating and detecting photons in large-scale. Here, we experimentally observe non-classical correlation of two identical photons in a fully coupled two-dimensional structure, i.e. photonic lattice manufactured by three-dimensional femtosecond laser writing. Photon interference consists of 36 Hong-Ou-Mandel interference and 9 bunching. The overlap between measured and simulated distribution is up to 0.890±0.001. Clear photon correlation is observed in the two-dimensional photonic lattice. Combining with controllably engineered disorder, our results open new perspectives towards large-scale implementation of quantum simulation on integrated photonic chips.
@article{arxiv.1606.05637,
title = {Non-classical photon correlation in a two-dimensional photonic lattice},
author = {Jun Gao and Lu-Feng Qiao and Xiao-Feng Lin and Zhi-Qiang Jiao and Zhen Feng and Zheng Zhou and Zhen-Wei Gao and Xiao-Yun Xu and Yuan Chen and Hao Tang and Xian-Min Jin},
journal= {arXiv preprint arXiv:1606.05637},
year = {2016}
}