Freiburg 2019 – wissenschaftliches Programm
FM 41.17: Poster
Dienstag, 24. September 2019, 16:30–18:30, Tents
Progress Towards an Al+ Quantum Logic Optical Clock — Johannes Kramer1, Fabian Dawel1, •Nicolas Spethmann1, Sara Panahandeh1, and Piet Schmidt1,2 — 1Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany — 2Leibniz Universität Hannover, 30167 Hannover, Germany
We present the status of our aluminum ion optical clock, based on a single 27Al+ clock ion trapped together with a 40Ca+ logic ion used for sympathetic cooling and quantum logic state readout. 27Al+ provides a narrow clock transition and low sensitivity to external field shifts. A measurement of the trap temperature combined with numerical simulations allows us to bound the black-body radiation shift to smaller than 10−19. Micromotion has been compensated to a level well below a fractional frequency uncertainty of 10−17. We developed double-bright electromagnetically induced transparency (D-EIT) cooling as a novel, fast multi-mode ground state cooling technique. Using D-EIT we demonstrated for the first time ground-state cooling of all three motional degrees of freedom of a trapped 40Ca+ ion within a single, short cooling pulse. Extrapolating from these results, we expect a fractional second order Doppler shift from residual motion of an Al+/Ca+ crystal of well below 10−18. We will present results of reading out the state of 27Al+ using quantum logic and progress towards quantum logic spectroscopy of the clock transition.