Ytterbium optical lattice clock with instability of order 10^?18

Abstract We have built an ytterbium optical lattice clock with improvements over our previous version. An in-vacuum blackbody radiation (BBR) shield is employed to provide a well characterized BBR environment. The effective temperature felt by the atoms can be determined at accuracy level of 13 mK, leading total frequency shift uncertainty 9.5 × 10 ?19 . also ultra-stable cavity system pre-stabilize laser, achieving flicker instability ?3 ?16 Rabi spectroscopy lattice-trapped achieve sub-Hertz linewidth spectra. Two clocks been operated in antisynchronized configuration, real-time BBR-Stark-shift corrections applied both them. By comparing two clocks, we demonstrate single-clock 5.4 ?18 4500 s. This will for comparisons other different atomic species future.