We demonstrate that the $4f^{14}6s6p\left({}^{3}P_2\right)-4f^{13}5d6s^2\left({}^{3}P_2^{*}\right)$ transition in neutral ytterbium (Yb) can serve as an additional clock transition with the highest fine-structure constant (${\alpha }_e$) varying sensitivity coefficient $[q=-46165(3000\left)\right]$. We demonstrate a scheme to attain simultaneous magic trapping conditions for this clock transition with other two proposed clock transitions $4f^{14}6s^2\left({}^{1}S_0\right)-{}^{3}P_2$ and ${}^{1}S_0-{}^{3}P_2^{*}$, which also possess very large $q$ values. These conditions can be realized by subjecting Yb atoms to a bias magnetic field with tuning the particular polarization angles of the trapping laser. Upon realization, it can serve as the most potential optical lattice clock to probe ${\alpha }_e$ variation.

The magnetic field is extremely important for understanding the properties of the solar corona. However, there are still difficulties in the direct measurement of the coronal magnetic field. The magnetic-field-induced transition (MIT) in Fe x, appearing in coronal spectra, was discovered to have prospective applications in coronal magnetic field measurements. In this work, we obtained the extreme ultraviolet spectra of Fe x in the wavelength range of 174–267 Å in the Shanghai High-temperature Superconducting Electron Beam Ion Trap, and examined the effect of MIT in Fe x by measuring the line ratios between 257.262 Å and the reference line of 226.31 Å (257/226) at different magnetic field strengths for the first time. The electron density that may affect the 257/226 value was also obtained experimentally and verified by comparing the density-sensitive line ratio (175.266 Å/174.534 Å) measurements with the theoretical predictions, and there was good agreement between them. The energy separation between the two levels of 3s²3p⁴3d ⁴ D _5/2 and 3s²3p⁴3d ⁴ D _7/2, one of the most critical parameters for determining the MIT rate, was obtained by analyzing the simulated line ratios of 257/226 with the experimental values at the given electron densities and magnetic fields. Possible reasons that may have led to the difference between the obtained energy splitting and the recommended value in previous works are discussed. Magnetic field response curves for the 257/226 value were calculated and compared to the experimental results, which is necessary for future MIT diagnostics.

The static and dynamic electric dipole polarizabilities of the 6 s 2 1 S 0 and 6 s 6 p 3 P 1 o states of Yb are calculated by using the relativistic ab initio method. Focusing on the red detuning region to the 6 s 2 1 S 0 – 6 s 6 p 3 P 1 o transition, we find two magic wavelengths at 1035.7(2) and 612.9(2) nm for the 6 s 2 1 S 0 – 6 s 6 p 3 P 1 o , M J = 0 transition and three magic wavelengths at 1517.68(6), 1036.0(3) and 858(12) nm for the 6 s 2 1 S 0 – 6 s 6 p 3 P 1 o , M J = ± 1 transitions. Such magic wavelengths are of particular interest for attaining the state-insensitive cooling, trapping, and quantum manipulation of neutral Yb atom.

The electric-dipole dynamic polarizabilities of the 6s ^{2 1} S ₀ and 6s6p ³ P ₁ states of Yb atom are calculated by using the CI+MBPT method. Magic wavelengths for the 6s ^{2 1} S ₀ - 6s6p ³ P ₁ transition are identified.