Strategies for reducing the light shift in atomic clocks

Recent progress in optical lattice clocks requires unprecedented precision in controlling systematic uncertainties at ${10}^{-18}$ level. Tuning of nonlinear light shifts is shown to reduce lattice-induced clock shift for wide range of lattice intensity. Based on theoretical multipolar, nonlinear, anharmonic and higher-order light shifts, we numerically demonstrate possible strategies for Sr, Yb, and Hg clocks to achieve lattice-induced systematic uncertainty below $1\times {10}^{-18}$.