High accuracy correction of blackbody radiation shift in an optical lattice clock

TL;DR

This paper presents a precise measurement and modeling of the blackbody radiation shift in strontium optical lattice clocks, significantly reducing the uncertainty and enhancing clock accuracy.

Contribution

It introduces a new method combining differential dc-polarizability measurement and dynamic modeling to correct blackbody radiation shifts in strontium clocks.

Findings

Blackbody radiation shift uncertainty reduced to 5×10⁻¹⁸

Differential dc-polarizability measured accurately

Modeling improves clock frequency correction

Abstract

We have determined the frequency shift that blackbody radiation is inducing on the $5s^2$ $^1$S$_0$ -- $5s5p$ $^3$P$_0$ clock transition in strontium. Previously its uncertainty limited the uncertainty of strontium lattice clocks to $1\times10^{-16}$. Now the uncertainty associated to the black body radiation shift correction translates to $5\times 10^{-18}$ relative frequency uncertainty at room temperature. Our evaluation is based on a measurement of the differential dc-polarizability of the two clock states and on a modeling of the dynamic contribution using this value and experimental data for other atomic properties.