We provide a new paradigm in chip-scale-integrated vapour cells by experimentally demonstrating the nanoatomic suspended waveguide, which introduces a nanoscale silicon nitride waveguide suspended in rubidium vapour. By doing so, the properties of the optical modes and the light–vapour interactions are controlled by the waveguide dimensions and can be tailored precisely for specific applications. Compared with previously published atomic cladded waveguides, our new device allows for a substantial reduction of Doppler and transit time broadening and improves the vapour coherence time.

https://www.nature.com/articles/s41566-021-00853-4