Correction to: Nature Physics https://doi.org/10.1038/s41567-020-1033-3, published online 21 September 2020.

In the PDF version of this Letter originally published, the equation for the cross-coupling term, FΔ−u, was incorrect: extraneous LaTeX code, ‘0.5em’, was included and part of the final term and closing parenthesis, ‘c.c.)’, was missing. The HTML version was correct. The PDF version of the Letter has now been corrected.