An optical lattice clock with accuracy and stability at the 10−18 level

In the search for stable and accurate atomic clocks, many-atom lattice clocks have shown higher precision than clocks based on single trapped ions, but have been less accurate; here, a stable many-atom clock is demonstrated that has accuracy better than single-ion clocks. Raising the standard for many-atom clocks Whether for the definition of SI units, testing the laws of physics or for applications yet to be dreamt of, scientists will always want more stability and more accuracy in their atomic clocks. Many-atom lattice clocks have achieved better precision than clocks based on single trapped ions, but their accuracy has so far been relatively poor. This study from the National Institute of Standards and Technology (NIST) demonstrates a many-atom clock that achieves better accuracy than single-ion-based clocks, and at the same time reduces the required measurement time by two orders of magnitude. Based on thousands of neutral strontium atoms trapped in a laser beam, this new 'optical lattice' clock has the stability, reproducibility and accuracy that make it a prime contender for consideration as a primary standard. It would neither gain nor lose one second in about 5 billion years — although the Earth is unlikely to last that long. Progress in atomic, optical and quantum science 1 , 2 has led to rapid improvements in atomic clocks. At the same time, atomic clock research has helped to advance the frontiers of science, affecting both fundamental and applied research. The ability to control quantum states of individual atoms and photons is central to quantum information science and precision measurement, and optical clocks based on single ions have achieved the lowest systematic uncertainty of any frequency standard 3 , 4 , 5 . Although many-atom lattice clocks have shown advantages in measurement precision over trapped-ion clocks 6 , 7 , their accuracy has remained 16 times worse 8 , 9 , 10 . Here we demonstrate a many-atom system that achieves an accuracy of 6.4 × 10 −18 , which is not only better than a single-ion-based clock, but also reduces the required measurement time by two orders of magnitude. By systematically evaluating all known sources of uncertainty, including in situ monitoring of the blackbody radiation environment, we improve the accuracy of optical lattice clocks by a factor of 22. This single clock has simultaneously achieved the best known performance in the key characteristics necessary for consideration as a primary standard—stabilit