Generation of multiphoton quantum states on silicon

Abstract

Multiphoton quantum states play a critical role in emerging quantum technologies and greatly improve our fundamental understanding of the quantum world. Integrated photonics is well recognized as an attractive technology offering great promise for the generation of photonic quantum states with high-brightness, tunability, stability, and scalability. Herein, we demonstrate the generation of multiphoton quantum states using a single-silicon nanophotonic waveguide. The detected four-photon rate reaches 0.34 Hz even with a low-pump power of 600 μW. This multiphoton quantum state is also qualified with multiphoton quantum interference, as well as quantum state tomography. For the generated four-photon states, the quantum interference visibilities are greater than 95%, and the fidelity is 0.78 ± 0.02. Furthermore, such a multiphoton quantum source is fully compatible with the on-chip processes of quantum manipulation, as well as quantum detection, which is helpful for the realization of large-scale quantum photonic integrated circuits (QPICs) and shows great potential for research in the area of multiphoton quantum science.

Photonics: Pairing-up for next generation photonic quantum technologies

Chinese scientists have developed a technique for generating photon-pairs for use in quantum devices, paving the way for a range of new photonic quantum technologies. Multi-photon quantum sources are critical for the development of new photonic quantum technologies, and drove Dao-Xin Dai and colleagues from Zhejiang University, in collaboration with researchers from the University of Science and Technology of China, to develop a technique that generates high-quality photonic quantum states. Using a method called spontaneous four-wave mixing, whereby three electromagnetic fields interact to produce a fourth field, the team created multi-photon quantum states in a silicon nanophotonic spiral waveguide. The technique produces bright, tunable, stable and scalable multi-photon quantum states, and is compatible with a current fiber and integrated circuit manufacturing processes, opening the door to new photonic quantum technologies in communications, computation, and imaging.