Correction to: Nature Physics https://doi.org/10.1038/s41567-018-0224-7, published online 30 July 2018.

In the version of this Article originally published, B. Andrei Bernevig was missing the following two additional affiliations: Physics Department, Freie Universitat Berlin, Berlin, Germany, and Max Planck Institute of Microstructure Physics, Halle, Germany. This has been corrected in the online versions of the Article.