Correction to: Nature Nanotechnology https://doi.org/10.1038/s41565-018-0277-x, published online 6 December 2018.

In the version of this Comment originally published, equation (4) contained the wrong inequality sign of \(\lesssim\) rather than \(\gtrsim \); the equation has now been corrected in the online versions of the Comment to read \(S\left( F \right) \equiv \frac{{z_{{\mathrm{inf}}}^2}}{4}\frac{{F^{\prime\prime \prime }\left( {z_{{\mathrm{inf}}}} \right)}}{{F^\prime \left( {z_{{\mathrm{inf}}}} \right)}} \gtrsim - 1\).