Continuous operation of a bicolor thulium optical lattice clock

Abstract

We discuss extension of a recently proposed method based on continuous spectroscopy of ⁸⁸Sr atoms trapped into a moving optical lattice [Appl. Phys. Express,14(7),072006(2021)] to operation of bicolor thulium optical clocks. Simultaneous interrogation of two clock transitions at 1.14μm and building up a synthetic frequency provides a straightforward way to significantly suppress the first-order Doppler shift and cancel out the second-order Zeeman shift, the latter being one of the major uncertainty sources in the originally proposed ⁸⁸Sr setup. In our configuration, the total systematic frequency shift is 4×10⁻¹⁶ and instability at or lower than 10⁻¹⁸ after 1 hour of integration.