Centre for Quantum Technologies, 3 Science Drive 2, Singapore, 117543, Singapore.
Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore.
Nat Commun. 2017 Oct 31;8(1):1200. doi: 10.1038/s41467-017-01495-3.
Implementing nonlinear interactions between single photons and single atoms is at the forefront of optical physics. Motivated by the prospects of deterministic all-optical quantum logic, many efforts are currently underway to find suitable experimental techniques. Focusing the incident photons onto the atom with a lens yielded promising results, but is limited by diffraction to moderate interaction strengths. However, techniques to exceed the diffraction limit are known from high-resolution imaging. Here we adapt a super-resolution imaging technique, 4Pi microscopy, to efficiently couple light to a single atom. We observe 36.6(3)% extinction of the incident field, and a modified photon statistics of the transmitted field-indicating nonlinear interaction at the single-photon level. Our results pave the way to few-photon nonlinear optics with individual atoms in free space.
实现单光子和单原子之间的非线性相互作用是光学物理的前沿领域。受确定性全光量子逻辑的前景的推动，目前正在努力寻找合适的实验技术。用透镜将入射光子聚焦到原子上取得了有希望的结果，但由于衍射的限制，相互作用强度适中。然而，高分辨率成像是众所周知的可以突破衍射极限的技术。在这里，我们采用一种超分辨率成像技术——4Pi 显微镜，有效地将光耦合到单个原子上。我们观察到入射场的 36.6(3)%的消光，以及透射场的改进的光子统计——这表明在单光子水平上存在非线性相互作用。我们的结果为在自由空间中用单个原子进行少光子非线性光学铺平了道路。
