Correction to: Nature https://doi.org/10.1038/s41586-019-1177-4Published online 15 May 2019

In the Acknowledgements of this Article, the text “and the Quantum Flagship PASQUANS” should be replaced with the sentence “This project (or publication) has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 817482 (PASQuanS).” The original Article has been corrected online.