Development of Room Temperature and Cryogenic Strontium Ion Clocks With Low Uncertainties

SummaryWe are developing a transportable room temperature strontium ion clock at the National Research Council Canada (NRC) and a laboratory-based cryogenic strontium ion clock at the University of Toronto. These clocks are designed to minimize the systematic frequency shifts and meet the mandatory accuracy criteria for the redefinition of the SI second. The expected performances of the new optical clocks are compared to the well-characterized NRC strontium ion frequency standard that has been operational for more than a decade.