Correction to: Nature Nanotechnology https://doi.org/10.1038/s41565-018-0122-2, published online 30 April 2018.

In the version of this Article originally published, an error during typesetting led to the curve in Fig. 2a being shifted to the right, and the curves in the inset of Fig. 2a being displaced. The figure has now been corrected in all versions of the Article; the original and corrected Fig. 2a are shown below.

Fig. 2a
figure 1

Original and corrected.