Correction to: Nature Physics https://doi.org/10.1038/s41567-019-0702-6, published online 11 November 2019.

In the version of this Perspective originally published, in Box 1, the sentence “The single particle in the high-energy site can move to the lower-energy site with rate p, but in doing so the system will lose energy ΔE.” has been amended to read “The single particle in the site with high energy E1 can move to the site with lower energy E2 with rate p, but in doing so the system will lose energy ΔE = E1E2.” Accordingly, also in Box 1, the following equation changes have been made. (1) In the equations for ‘ \(\frac{\alpha }{\gamma }\) ’ and ‘\(\frac{\beta }{\delta }\) ’, the superscripts ‘μleft/kBT’ and ‘−μrightkBT’, respectively, should have been ‘(μleftE1)/kBT’ and ‘−(μrightE2)/kBT’; the correct equations are ‘\(\frac{\alpha }{\gamma } = e^{\left( {\mu _{{\mathrm{left}}} - E_1} \right){\mathrm{/}}k_{\mathrm{B}}T}\)’ and ‘\(\frac{\beta }{\delta } = e^{ - \left( {\mu _{{\mathrm{right}}} - E_2} \right){\mathrm{/}}k_{\mathrm{B}}T}\)’. (2) In the equation in the sentence beginning “For example:”, the term ‘\(+ \frac{{\Delta E}}{{k_{\mathrm{B}}T}}\)’ should not have been included; the correct equation is:

The online versions of the Perspective have been amended.