CM - AMO SEMINAR | Higher-Order Constraints on Precision of Clocks of Neutral Atoms in Optical Lattices

The recent progress in designing optical frequency standards with an uncertainty at a level of 10^-17 – 10^-18 requires unprecedented accuracy in estimating the role of higher-order uncertainties of optical clocks. The magic wavelength (MWL) of the optical lattice, capable to trap deeply cooled alkaline-earth-like atoms to a Lamb-Dicke regime, enables observation of Doppler- free and Stark-free clock transition between the ground state ¹S₀ and excited metastable state ³P₀. In this paper, the difference between spatial distributions of electric-dipole (E1) and multipole (M1 and E2) is presented explicitly in two lattices: the attractive red-detuned and repulsive blue-detuned lattices. For simplicity, a 1D lattice is considered. Calculations of the clock-frequency shifts in trapped atoms are presented. The magnitudes of uncertainties are determined, arising from the nonlinear and non-dipole corrections to the lattice-induced shifts, which cannot be compensated by the MWL and therefore should be determined and taken into account in high-precision measurements of the clock frequency. We systematically evaluate the multipole, nonlinear, and anharmonic contributions to uncertainty of the optical-lattice-based clocks of alkaline-earth-like-atoms Sr, Yb and Hg.