High-Accuracy Optical Clock via Three-Level Coherence in Neutral BosonicSr88

An optical atomic clock scheme is proposed that utilizes two lasers to establish coherent coupling between the $5s^2{}^{1}S_0$ ground state of ${}^{88}\mathrm{Sr}$ and the first excited state, $5s5p{}^{3}P_0$. The coupling is mediated by the broad $5s5p{}^{1}P_1$ state, exploiting the phenomenon of electromagnetically induced transparency. The effective linewidth of the clock transition can be chosen at will by adjusting the laser intensity. By trapping the ${}^{88}\mathrm{Sr}$ atoms in an optical lattice, long interaction times with the two lasers are ensured; Doppler and recoil effects are eliminated. Based on a careful analysis of systematic errors, a clock accuracy of better than $2\times {10}^{-17}$ is expected.