Extended Data Fig. 3: Systematic shifts of the Zeeman component 19+ of the rotational hyperfine transition line 19.
From: Precise test of quantum electrodynamics and determination of fundamental constants with HD+ ions
a, The trap’s amplitude is decreased by 2.5 V from \({V}_{{\rm{RF}}}^{(1)}\) to \({V}_{{\rm{RF}}}^{(2)}\). The FWHM linewidth is 4 Hz, corresponding to 3 × 10−12 fractional FWHM. b, The light shift induced by the 266 nm and 1.4 μm dissociation lasers, determined by comparing two spectroscopy modes. ‘Continuous’ indicates that the lasers are on when the terahertz radiation is applied. ‘Interleaved’ indicates that the lasers and terahertz radiation are on alternatingly.
