Hyper-precise atomic clocks face off to redefine time

Photograph of optical clock

A recently-published article in  Nature describes the work of EMRP project SIB55 'International timescales with optical clocks', which uses a broadband two-way satellite time and frequency transfer (TWSTFT) link to compare optical clocks at INRIM (Italy), LNE-SYRTE (France), NPL (UK) and PTB (Germany). Nature is the leading weekly, international scientific journal with over 6 million visitors per month.The SI second is currently defined in terms of a transition frequency in the caesium atom. However the most advanced optical atomic clocks have now reached levels of stability and uncertainty that significantly surpass the performance of caesium primary standards.

Comparison exercises such as this are needed to build confidence in the new generation of optical clocks by validating their performance levels, to anchor their frequencies to the present definition of the second with the lowest possible uncertainty, and to establish the leading contenders for a new definition of the second.

SIB55 coordinator Helen Margolis, NPL, and partner Fritz Riehle, PTB, are quoted in the article. Margolis spoke of future plans to conduct an even more accurate optical clock comparison using fibre-optics, with Riehle adding: “Europe is in a unique position as it has a high density of the best clocks in the world.”

The article can be found here


Select your area of interest
EMPIR project brings documentary standardisation to Ion gauges

Completed in 2020 the Ion Gauge project continues to bring standardisation to vacuum measurements more

Good practice guide on the analysis of thin films now available

Half of the EU’s energy is imported from abroad. An EMPIR project has helped address this situation. more

EMPIR project contributes to committee revising LED lighting standards

LED lighting expert from an EMPIR project consortium chairs a new technical committee approved to revise key standards more

Partnership Call 2023: Call for Needs Open

EURAMET announces the launch of the 2023 Call for Needs within the European Partnership on Metrology: more

Measurements for next-generation digital substation instrumentation

EMPIR project develops measurement methods needed for power distribution and transmission more

Page 1 of 199.