Mainz 2026 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 53: Precision Spectroscopy of Atoms and Ions IV (joint session A/Q)
Q 53.7: Talk
Thursday, March 5, 2026, 12:45–13:00, N 3
Assessment of the differential polarizability of Yb+ and Sr+ clock transitions — •Martin Steinel1, Thomas Lindvall2, Marianna Safronova3, Melina Filzinger1, Jian Jiang1, Saaswath JK1, Ekkehard Peik1, and Nils Huntemann1 — 1Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig — 2VTT Technical Research Centre of Finland, National Metrology Institute VTT MIKES, P.O. Box 1000, 02044 VTT, Finland — 3University of Delaware, Newark, USA
Optical clocks are leading candidates for a redefinition of the second, with estimated fractional uncertainties at the 6 × 10−19 level [1]. Room-temperature 171Yb+ clocks operating on the S1/2 → F7/2 electric-octupole (E3) transition currently reach 3 × 10−18 [2], limited by the blackbody-radiation (BBR) shift ΔνBBR ∝ Δα T4. The dominant uncertainty arises from the ∼ 2% accuracy of the differential polarizability Δα, determined from measurements of the light shift induced by an infrared laser with calibrated optical power and in-situ estimate of the beam profile. In contrast, a method balancing the Stark and Doppler shift caused by excess micromotion yields a Δα uncertainty of 0.04% for 88Sr+ [3]. We present direct comparisons of both techniques using 88Sr+ and determine the ratio of Δα for 171Yb+ and 88Sr+, enabling a potential reduction of the E3 BBR-shift uncertainty to 2 × 10−19.
[1] M. C. Marshall et al., Phys. Rev. Lett. 135, 033201 (2025) [2] N. Huntemann et al., Phys. Rev. Lett. 116, 063001 (2016) [3] T. Lindvall et al., Phys. Rev. Lett. 135, 043402 (2025)
Keywords: Optical clock; Black body radiation; Polarizability; Multi-ion clock; Intensity calibration