Improved Frequency Measurement of a One-Dimensional Optical Lattice Clock with a Spin-Polarized Fermionic⁸⁷Sr Isotope

Abstract

We demonstrate a one-dimensional optical lattice clock with a spin-polarized\nfermionic isotope designed to realize a collision-shift-free atomic clock with\nneutral atom ensembles. To reduce systematic uncertainties, we developed both\nZeeman shift and vector light-shift cancellation techniques. By introducing\nboth an H-maser and a Global Positioning System (GPS) carrier phase link, the\nabsolute frequency of the $^1S_0(F=9/2) - {}^3P_0(F=9/2)$ clock transition of\nthe $^{87}$Sr optical lattice clock is determined as 429,228,004,229,875(4) Hz,\nwhere the uncertainty is mainly limited by that of the frequency link. The\nresult indicates that the Sr lattice clock will play an important role in the\nscope of the redefinition of the ``second'' by optical frequency standards.\n