Investigation of the 6s6p ^{3}P_{0}-4f^{13}5d6s^{2} (J=2) Clock Transition in ^{171}Yb Atoms

Abstract

High-precision atomic spectroscopy provides an invaluable and sensitive tool for exploring a wide range of physical questions. Here, we investigate the forbidden optical transition of the 6s6p^{3}P_{0}-4f^{13}5d6s^{2} (J=2) in ^{171}Yb atoms at the wavelength of 1695 nm, which exhibits the highest sensitivity to the variation of the fine-structure constant α compared to the current neutral optical clock. We obtain high-resolution transition spectroscopy in a one-dimensional optical lattice, and the measurement of its absolute frequency achieves kHz-level accuracy. Meanwhile, several essential atomic constants are also determined, including the electric-dipole (E1) magic wavelengths, as well as the hyperpolarizabilities and tensor polarizabilities around the E1 magic wavelengths. Additionally, we derive the hyperfine constant for the J=2 state from the measured absolute frequencies 1123 252.3±2.0 kHz, providing a sixfold enhancement in the uncertainty reduction compared to the recent result. We anticipate that this work will prompt further investigation of the additional clock transition at 1695 nm in ^{171}Yb atoms. Together with the well-established ^{1}S_{0}-^{3}P_{0} transition, many fundamental and new physics research, such as the time variation of α, ultralight dark-matter searches, Lorentz violation, etc., will enable new bounds and measurements with unprecedented precision.