S. Alighanbari

Abstract The molecular hydrogen ions (MHI) are three-body systems suitable for advancing our knowledge in several domains: fundamental constants, tests of quantum physics, search for new interparticle forces, tests of the weak equivalence principle1 and, once the anti-molecule \(\overline{p}\,\overline{p}\,{e}^{+}\) becomes available, new tests of charge–parity–time-reversal invariance and local position invariance1,2,3.

Correction to: Nature Physics https://doi.org/10.1038/s41567-020-01150-7, published online 18 February 2021 In the published article, we erroneously based parts of our analysis on a preliminary value of the theoretical spin-averaged frequency and its QED uncertainty, and not on the value given in eq. (7). As a consequence, two expressions must be corrected.

Abstract Comparison of precise predictions of the energy levels of the molecular hydrogen ion \({\rm{H}}_{2}^{+}\)—the simplest molecule—with measured vibrational transition frequencies would allow a direct determination of the proton-to-electron mass ratio and of the proton’s charge radius. Here we report vibrational laser spectroscopy of trapped and sympathetically laser-cooled \({{{{\rm{H}}}}}_{2}^{+}\), which represents a step towards this goal.