Correction to: Nature Physics, published online 14 February 2024.

In the version of the article initially published, references 87 and 88 were mistakenly swapped. They have now been corrected so that reference 87 is “Willsch, D. & Rieger, D. Spectroscopy data and model parameters for ‘Observation of Josephson harmonics in tunnel junctions’. Jülich DATA (2023)” and 88 is “Jülich Supercomputing Centre JUWELS cluster and booster: exascale pathfinder with modular supercomputing architecture at Juelich Supercomputing Centre. JLSRF 7, A138 (2021).” This change has been made to the HTML and PDF versions of the article.