Real-Space Imaging of Thomson Charge Configurations in Superfluid Helium Nanodroplets

Predicting the lowest-energy arrangement of like charges on a sphere defines the Thomson problem, a long-standing challenge with analytical solutions only for a few small systems. We report a real-space experimental realization using superfluid helium nanodroplets, where surface-localized charges are tagged by singly charged gold nanoparticles and recorded as transmission electron microscopy imprints. The observed configurations reveal Thomson charge ordering from finite-N minima to curvature-frustrated Coulomb crystallization, establishing helium nanodroplets as a directly imageable platform for charge organization on spherical surfaces.