TOKYO – Optical lattice clocks developed by a Japanese scientist have emerged as a leading candidate in discussions by an international body to redefine the second.
The General Conference on Weights and Measures to be held in France next month will identify remaining issues, with a new definition and implementation schedule to be proposed as early as 2030.
Optical lattice clocks trap thousands of atoms individually in an “egg carton” grid formed by intersecting laser beams. The clocks measure the frequency of light absorbed by the atoms, cooled to nearly absolute zero, all at once.
The clocks, which use atoms such as strontium and ytterbium, lose or gain only about one second over 30 billion years, far surpassing the precision of cesium atomic clocks currently used to define the second.
Hidetoshi Katori, a University of Tokyo professor who developed a strontium optical lattice clock, is widely regarded as a strong potential candidate for the Nobel Prize in Physics.
A redefinition of a second could enable more precise experiments and observations in physics and astronomy, including research into dark matter.
It could also support next-generation positioning systems, crustal movement monitoring and underground resource exploration.
As various types of optical lattice clocks and single-ion optical clocks exist, researchers must conduct rigorous comparisons across countries and institutions before deciding on one system or combining several.
“Challenges include ensuring (the clocks) keep operating without maintenance and how to make them smaller. Adoption for the definition of the second would mark a major step toward their practical use,” said Katori.