The authors of the paper “Epitaxy of advanced nanowire quantum devices”¹ wish to retract this work. When preparing the underlying data for public release², it was discovered that some data had been inappropriately deleted or cropped when preparing the final published figures, and we promptly alerted the editors of Nature. We found unjustified data removal and cropping in Figures 4a and c, and Extended Data Figures 7 and 8, which affect the agreement between the theoretical curves and the experimental data and the claims of ballistic transport. We are accordingly retracting the paper. The authors stand by all the other data, and their contribution to advanced nanowire quantum devices. All authors have agreed to this retraction.