An optical lattice clock with spin-polarized 87Sr atoms

We present a new evaluation of an Sr-87 optical lattice clock using spin polarized atoms. The frequency of the S-1(0) -> P-3(0) clock transition is found to be 429 228 004 229 873.6 Hz with a fractional uncertainty of 2.6x10(-15), a value that is comparable to the frequency difference between the various primary standards throughout the world. This measurement is in excellent agreement with a previous one of similar accuracy.