Extraordinary low systematic frequency shifts in bi-colour thulium optical clock

Abstract

Optical atomic clocks have already overcome the eighteenth decimal digit of instability and uncertainty demonstrating incredible control over external perturbations of the clock transition frequency. At the same time there is an increasing demand for atomic and ionic transitions with minimal sensitivity to external fields, with practical operational wavelengths and robust readout protocols. One of the goals is to simplify clock's operation maintaining its relative uncertainty at low 10-18 level. It is especially important for transportable and envisioned space-based optical clocks. We proved earlier that the 1.14um inner-shell magnetic dipole transition in neutral thulium possesses very low blackbody radiation shift compared to other neutrals. Here we demonstrate operation of a bi-colour thulium optical clock with extraordinary low sensitivity to the Zeeman shift due to a simultaneous interrogation of two clock transitions and data processing. Our experiment shows suppression of the quadratic Zeeman shift by at least three orders of magnitude. The effect of tensor lattice Stark shift can be also reduced to below 10-18 in fractional frequency units. All these features make thulium optical clock almost free from hard-to-control systematic shifts. Together with convenient cooling and trapping laser wavelengths, it provides great perspectives for thulium lattice clock as a high-performance transportable system.

arXiv comment25 pages, 9 figures

References in corpus (16)

• Systematic evaluation of an atomic clock at 2e-18 total uncertainty
• Atomic clock performance beyond the geodetic limit
• Geodesy and metrology with a transportable optical clock
• Optical clock intercomparison with $6\times 10^{-19}$ precision in one hour
• Frequency ratio of two optical clock transitions in ${}^{171}$Yb${}^{+}$ and constraints on the time-variation of fundamental constants
• A clock network for geodesy and fundamental science
• Ultra-stable optical clock with two cold-atom ensembles
• JILA SrI Optical Lattice Clock with Uncertainty of $2.0\times 10^{-18}$
• Precision Metrology Meets Cosmology: Improved Constraints on Ultralight Dark Matter from Atom-Cavity Frequency Comparisons
• Improved limits for violations of local position invariance from atomic clock comparisons
• Demonstration of a time scale based on a stable optical carrier
• Blackbody radiation shift assessment for a lutetium ion clock
• Optical frequency ratio of a ${}^{171}{\mathrm{Yb}}^{+}$ single-ion clock and a ${}^{87}\mathrm{Sr}$ lattice clock
• Inner-shell magnetic dipole transition in Tm atom as a candidate for optical lattice clocks
• Simultaneous two initial clock states preparation for thulium optical clock
• Frequency Ratio Measurements with 18-digit Accuracy Using a Network of Optical Clocks