Improved frequency measurement of the $^1S_{0}$-$^3P_{0}$ clock transition in $^{87}$Sr using the Cs fountain clock at NMIJ as a transfer oscillator

摘要

We performed an absolute frequency measurement of the $^1S_{0}$-$^3P_{0}$transition in $^{87}$Sr with a fractional uncertainty of $1.2 \times 10^{-15}$,which is less than one third that of our previous measurement. A caesiumfountain atomic clock was used as a transfer oscillator to reduce theuncertainty of the link between a strontium optical lattice clock and the SIsecond. The absolute value of the transition frequency is 429 228 004 229873.56(49) Hz.