Correction to: Nature Communications https://doi.org/10.1038/s41467-019-13332-w, published online 09 December 2019.

The original version of this Article contained an error in the second and third sentences of the legend of Fig. 4, which incorrectly read ‘Superradiant emission of GeV centres coupled to a single-mode waveguide. The bunching signature with g2 > 1 (lower left) indicates cooperative emission between two separated GeV centres’. The correct version states ‘Homodyne interferometry with a single GeV centre (top panel). Interference between GeV resonance fluorescence and near-resonant excitation laser light reflected in the fibre by the Bragg mirror. Varying their relative amplitude and phase, by modifying the polarization of the input laser, results in the change in line shape of the output light (mid panel) from symmetric, corresponding to destructive interference (orange) to dispersive (blue). The Hanbury Brown-Twiss interferometry measurement (bottom panel) shows g2(0) > 1 due to interference between the excitation laser and the resonant fluorescence from the single GeV centre. It highlights the quantum nonlinear character of the coupled GeV-waveguide system’. This has been corrected in both the PDF and HTML versions of the Article.