Correction to: Nature Communications https://doi.org/10.1038/s41467-019-08518-1, published online 1 Feb 2019.

The original version of this Article contained an error in the right-hand y-axis of Fig. 2c, which incorrectly read ‘S/2e (pA)’. The correct version states ‘nA’ in place of ‘pA’. This has been corrected in both the PDF and HTML versions of the Article.