Atom-based photonics

Aoki, Takao, Waseda Univ.

doi:10.1117/3.100307.ch8

Book: Quantum Photonics

Editor(s): Yasuhiko Arakawa; Dieter Bimberg

Chapter Author(s): Takao Aoki

Published: 2024

https://doi.org/10.1117/3.100307.ch8

Author Affiliations +

Abstract

Atoms are indispensable elements in quantum photonics, and the interaction of atoms and light offers a variety of useful quantum-photonic functions. An atom can absorb or emit only one photon at a time through its electronic transition because of the unharmonic nature of the Coulomb potential. Therefore, an atom is an ideal source of single photons. The unharmonicity of the Coulomb potential also yields strong optical nonlinearity at the single-photon level, and this can be utilized for quantum gates. Dissipations can be reduced and the atomic states with long coherence times can be utilized for quantum memories when the atoms are laser cooled and trapped in vacuum. The performance of these quantum photonic functions can be enhanced by using high-finesse cavities or nanophotonic structures that can confine light in small volumes and enhance atom-light interactions. A large-scale quantum network can be constructed by combining these functions. In this chapter, we focus on laser-cooled atoms (mainly neutral atoms, with some reference to ions) and review their applications in quantum photonics.