Correction to: Nature Nanotechnology https://doi.org/10.1038/s41565-018-0164-5, published online 6 June 2018.

In the version of this News and Views article originally published, in the author’s e-mail address, the domain was incorrectly given as ‘e-mail.arizona.edu’; it should have read ‘email.arizona.edu’. This has now been corrected in the online versions.