Physics: An atomic clock with record accuracy

An atomic clock that sets a new record in accuracy is reported online in Nature Communications. The optical lattice clock, which uses a lattice of strontium atoms, is approximately three times more accurate than the current record for the most accurate timekeeping.

Advanced laser stabilization techniques and novel atom trapping schemes have all improved dramatically in recent years. Bringing these tools to bear on optical lattice clocks has allowed Jun Ye and colleague to achieve better stability and lower uncertainty in their clock than other types of atomic clock. They report an optical lattice atomic clock, consisting of a lattice of ultracold strontium atoms that are isolated from external fields and perturbations by an ultrastable laser, providing record stability. This enhanced stability will not only bring clock accuracy to a new level but also brings optical lattice clocks closer to the point of replacing the current standard of measurement, the caesium fountain clock.