An Atomic Clock with 10 ^–18 Instability

TLDR

Atomic clocks have transformed science and technology, and next‑generation optical clocks aim for 1 part in 10^18 precision. The authors set out to develop and operate two optical lattice clocks based on spin‑polarized, ultracold ytterbium atoms. They realize these clocks as optical lattice systems that trap and interrogate spin‑polarized ultracold Yb atoms. Comparing the two clocks yielded an unprecedented instability of 1.6 × 10^−18 after only seven hours, opening possibilities for relativistic geodesy, advanced navigation, telescopy, and tests beyond the Standard Model.

Abstract

Atomic clocks have been transformational in science and technology, leading to innovations such as global positioning, advanced communications, and tests of fundamental constant variation. Next-generation optical atomic clocks can extend the capability of these timekeepers, where researchers have long aspired toward measurement precision at 1 part in $\bm{10^{18}}$. This milestone will enable a second revolution of new timing applications such as relativistic geodesy, enhanced Earth- and space-based navigation and telescopy, and new tests on physics beyond the Standard Model. Here, we describe the development and operation of two optical lattice clocks, both utilizing spin-polarized, ultracold atomic ytterbium. A measurement comparing these systems demonstrates an unprecedented atomic clock instability of $\bm{1.6\times 10^{-18}}$ after only $\bm{7}$ hours of averaging.