Correction to: Nature Physics https://doi.org/10.1038/s41567-023-01966-z. Published online 2 March 2023.

In the version of this article initially published, there was an error in the last sentence of the “Sample geometry and thermometry” subsection of Methods, where in the text now reading “The calibration is extrapolated to other pressures assuming “\({{{\mathcal{C}}}} \propto p_F^4\),” only “\({{{\mathcal{C}}}}\)” appeared; the sentence has been amended in the HTML and PDF versions of the article.