title: Erratum for the Report "Polariton superfluids reveal quantum hydrodynamic solitons" by A. Amo, S. Pigeon, D. Sanvitto, V. G. Sala, R. Hivet, I. Carusotto, F. Pisanello, G. Leménager, R. Houdré, E. Giacobino, C. Ciuti, A. Bramati.