Heidelberg 2015 – wissenschaftliches Programm
A 35.6: Poster
Donnerstag, 26. März 2015, 17:00–19:00, C/Foyer
Approaching 10−19 relative frequency uncertainty with an optical clock based on ion Coulomb crystals — •Tobias Burgermeister1, Jonas Keller1, Dimitri Kalincev1, Miroslav Doležal2, Petr Balling2, and Tanja E. Mehlstäubler1 — 1Physikalisch-Technische Bundesanstalt, Braunschweig, Germany — 2Czech Metrology Institute, Prague, Czech Republic
Single ion optical clocks are fundamentally limited in stability by quantum projection noise and require days or weeks of averaging to resolve frequencies with 10−18 uncertainty. We want to show that it is possible to increase the stability by building a clock based on ion Coulomb crystals with 115In+ ions sympathetically cooled by 172Yb+ ions.
Therefore we developed a chip-based linear Paul trap design, which is optimized for minimum axial micromotion [1,2]. Using a prototype trap made out of Rogers4350 we compare different techniques for micromotion minimization and show that we can measure micromotion amplitudes corresponding to fractional frequency shifts of below 10−19 for 115In+. In the prototype trap a heating rate of less than 2 phonons/s at a trap frequency of 500 kHz was observed.
With an advanced next generation ion trap based on gold coated AlN wafers experiments and simulations of the trap temperature rise due to the applied high RF voltage have been carried out at CMI, Prague. From first results we expect a fractional frequency uncertainty due to black-body radiation of the trap on the level of a few 10−19.
 Herschbach et al., Appl. Phys. B 107, 891 (2012)
 Pyka et al., Appl. Phys. B 114, 231 (2013)