A dual-species optical clock to investigate variations of the fine-structure constant and test local position invariance

Martin Steinel*, Hu Shao, Thomas Lindvall, Melina Filzinger, Richard Lange, Tanja E. Mehlstäubler, Ekkehard Peik, Nils Huntemann

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

    Abstract

    Optical clocks realize transition frequencies between atomic energy levels with a relative uncertainty below 10-18. Frequency ratio measurements between optical clocks can reach even lower uncertainties if systematic shifts are common mode for the atomic references like environmental disturbances or result from the same atomic parameter. This precision can be used to search for violations of local position invariance by exploiting the dependence of transition frequencies on fundamental constants like the fine structure constant α. An ion particularly suited to this task is 171Yb+
    . It provides two optical clock transitions from the ground state to the first and second excited state, an electric octupole (E3) transition and an electric quadrupole (E2) transition, respectively. Because of the large mass of the ion, both transition frequencies show a large sensitivity on a variation of α and the difference in the electronic structure of the two excited states leads to a dependence of opposite sign. Repeated measurements of the ratio of the two transition frequencies provide the most stringent limits on temporal drifts of α and a potential dependence on the gravitational field [1]. To further enhance the performance of the 171Yb+ clocks and clearly distinguish clock shifts from variations of α, we employ 88Sr+ co-trapped in the same apparatus. 88Sr+ also features an E2 clock transition but its frequency only weakly depends on α. Furthermore, this ion can be used for sympathetic cooling and to investigate systematic frequency shifts of the 171Yb+ E3 transition on a magnified scale. We present progress towards combined clock operation with both species and a first precise measurement of the ratio of the 88Sr+ E2 and the 171Yb+ E3 transition frequencies. Here, we demonstrate an in-situ evaluation of the effective temperature of thermal radiation perturbing the ion and of oscillating magnetic fields using 88Sr+
    .
    Original languageEnglish
    Title of host publicationHigh-precision measurements and searches for New Physics
    Subtitle of host publication766. WE-Heraeus-Seminar
    PublisherWilhelm and Else Heraeus Foundation
    Pages87-87
    Number of pages1
    Publication statusPublished - 2022
    MoE publication typeNot Eligible
    Event766. WE-Heraeus-Seminar: High-Precision Measurements and Searches for New Physics - Physikzentrum Bad Honnef, Bad Honnef, Germany
    Duration: 9 May 202213 May 2022

    Conference

    Conference766. WE-Heraeus-Seminar: High-Precision Measurements and Searches for New Physics
    Country/TerritoryGermany
    CityBad Honnef
    Period9/05/2213/05/22

    Fingerprint

    Dive into the research topics of 'A dual-species optical clock to investigate variations of the fine-structure constant and test local position invariance'. Together they form a unique fingerprint.

    Cite this