Correction to: Nature Physics, published online 2 May 2022.

In the originally published version of this article, in Fig. 3b, all the roman labels now appearing as “B,” “P” and “iX” appeared initially as Greek beta, pi and chi symbols. The labels have been restored. Further, the URL in ref. 23 led to an IBM documentation page but should instead have been listed as The changes have been made to the HTML and PDF versions of the article.