Ball-Lightning-like Relativistic Terahertz Solitons

This dataset comprises the core experimental measurements of the relativistic terahertz (THz) electromagnetic (EM) soliton. It includes: spatiotemporal image sequences capturing the formation and macroscopic lifetime (~100 ns) of the luminous plasma sphere (Fig. 1d); time-resolved, spectrally-filtered luminosity data tracking the evolution from Ar⁺ to Ar-dominated emission (Fig. 2); quantitative measurements of the soliton's expansion radius versus time, following the adiabatic 'snowplow' model (Fig. 3a); and time-evolving emission spectra (from ultraviolet to infrared) documenting its radiative cooling and the associated shift from ion line radiation to neutral-atom fluorescence (Fig. 4). Together, these data systematically characterize the soliton’s formation, sustained confinement, spatial dynamics, and spectral evolution, supporting the formation of a long-lived, ball-lightning-like relativistic THz soliton.