Roadmap towards the redefinition of the second

N Dimarcq; M Gertsvolf; Mileti, Gaetano; S Bize; C W Oates; E Peik; D Calonico; T Ido; P Tavella; F Meynadier; G Petit; G Panfilo; J Bartholomew; P Defraigne; E A Donley; P O Hedekvist; I Sesia; M Wouters; P Dubé; F Fang

doi:10.1088/1681-7575/ad17d2

Roadmap towards the redefinition of the second

Author(s)

N Dimarcq

M Gertsvolf

Mileti, Gaetano

Laboratoire temps-fréquence

S Bize

C W Oates

E Peik

D Calonico

T Ido

P Tavella

F Meynadier

G Petit

G Panfilo

J Bartholomew

P Defraigne

E A Donley

P O Hedekvist

I Sesia

M Wouters

P Dubé

F Fang

F Levi

J Lodewyck

H S Margolis

D Newell

S Slyusarev

S Weyers

J-P Uzan

M Yasuda

D-H Yu

C Rieck

H Schnatz

Y Hanado

M Fujieda

P-E Pottie

J Hanssen

A Malimon

N Ashby

Date issued

January 22, 2024

In

Metrologia

Vol

61

No

1

From page

1

To page

19

Abstract

This paper outlines the roadmap towards the redefinition of the second, which was recently updated by the CCTF Task Force created by the CCTF in 2020. The main achievements of optical frequency standards (OFS) call for reflection on the redefinition of the second, but open new challenges related to the performance of the OFS, their contribution to time scales and UTC, the possibility of their comparison, and the knowledge of the Earth's gravitational potential to ensure a robust and accurate capacity to realize a new definition at the level of 10−18 uncertainty. The mandatory criteria to be achieved before redefinition have been defined and their current fulfilment level is estimated showing the fields that still needed improvement. The possibility to base the redefinition on a single or on a set of transitions has also been evaluated. The roadmap indicates the steps to be followed in the next years to be ready for a sound and successful redefinition.