Entanglement is a counterintuitive feature of quantum physics that is at the heart of quantum technology. High-dimensional quantum states offer unique advantages in various quantum information tasks. Integrated photonic chips have recently emerged as a leading platform for the generation, manipulation and detection of entangled photons. Here, we report a silicon photonic chip that uses novel interferometric resonance-enhanced photon-pair sources, spectral demultiplexers and high-dimensional reconfigurable circuitries to generate, manipulate and analyse path-entangled three-dimensional qutrit states. By minimizing on-chip electrical and thermal cross-talk, we obtain high-quality quantum interference with visibilities above 96.5% and a maximumly entangled qutrit state with a fidelity of 95.5%. We further explore the fundamental properties of entangled qutrits to test quantum nonlocality and contextuality, and to implement quantum simulations of graphs and high-precision optical phase measurements. Our work paves the path for the development of multiphoton high-dimensional quantum technologies.
@article{arxiv.1911.08807,
title = {Three-dimensional entanglement on a silicon chip},
author = {Liangliang Lu and Lijun Xia and Zhiyu Chen and Leizhen Chen and Tonghua Yu and Tao Tao and Wenchao Ma and Ying Pan and Xinlun Cai and Yanqing Lu and Shining Zhu and Xiao-Song Ma},
journal= {arXiv preprint arXiv:1911.08807},
year = {2021}
}