Two-species composite atomic clocks

Project: EU project

Project Details


Supporting the use of multi-species atomic clocks as future SI standards

Clocks and frequency standards are the most precise measurement devices available. While today’s best optical clocks rely on the use of a single atomic reference transition, two-species composite atomic clocks promise to achieve even better performance.

Project will focus on metrology research necessary to support the use of multi-species atomic clocks as future SI standards.

VTT MIKES investigates novel interrogation sequences for two-species, ion-based optical clocks, measures frequency shifts induced by laser radiation and assesses DC and AC Zeeman effects in single ion traps.

Call 2020: Fundamental Metrology

This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.
Effective start/end date1/05/2130/04/24

Collaborative partners

  • German National Metrology Institute (PTB) (lead)
  • BA66 National metrology institute VTT MIKES
  • Bundesamt für Eich- und Vermessungswesen (BEV) (Project partner)
  • National Metrological Institute (INRIM) (Project partner)
  • National Physical Laboratory (NPL) (Project partner)
  • National Research Council (CNR) (Project partner)
  • Institute of Scientific Instruments of the CAS, v.v.i. (ISI) (Project partner)
  • Leibniz University Hannover (Project partner)
  • Max Planck Society (Project partner)
  • Vienna University of Technology (TU Wien) (Project partner)
  • Nicolaus Copernicus University (Project partner)


  • EURAMET e.V.


  • atomic clock
  • optical clock
  • SI second