Absolute frequency measurement of the 2 S 1/2 → 2 F 7/2 optical clock transition in 171 Yb+ with an uncertainty of 4 x 10 -16 using a frequency link to international atomic time

Baynham, C.Godun, R.Jones, J.King, S.Nisbet-Jones, P.Baynes, F.Rolland, A.Baird, P.Bongs, K.Gill, P.Margolis, H.2020-11-162020-11-162018Journal of Modern Optics, 2018; 65(5-6):585-5910950-03401362-3044http://hdl.handle.net/2440/129018The highly forbidden 2S1/2→2F7/2 electric octupole transition in 171Yb+ is a potential candidate for a redefinition of the SI second. We present a measurement of the absolute frequency of this optical transition, performed using a frequency link to International Atomic Time to provide traceability to the SI second. The 171Yb+ optical frequency standard was operated for 76% of a 25-day period, with the absolute frequency measured to be 642 121 496 772 645.14(26) Hz. The fractional uncertainty of 4.0×10−16 is comparable to that of the best previously reported measurement, which was made by a direct comparison to local caesium primary frequency standards.en© 2017 Informa UK Limited, trading as Taylor & Francis GroupFrequency metrology; optical frequency standards; international atomic timeAbsolute frequency measurement of the 2 S 1/2 → 2 F 7/2 optical clock transition in 171 Yb+ with an uncertainty of 4 x 10 -16 using a frequency link to international atomic timeAbsolute frequency measurement of the (2 S 1/2 → 2 F 7/2) optical clock transition in (171 Yb+) with an uncertainty of (4 x 10 -16) using a frequency link to international atomic timeJournal article003007685310.1080/09500340.2017.13845142-s2.0-850435895472-s2.0-85030872887372310