Hannover 2013 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 20: Poster: Precision spectroscopy of atoms and ions (with Q)

A 20.13: Poster

Dienstag, 19. März 2013, 16:00–18:30, Empore Lichthof

A Radium Ion Optical Clock — •Elwin A. Dijck, M. Nuñez Portela, O. Böll, S. Hoekstra, K. Jungmann, A. Mohanty, C.J.G. Onderwater, R.G.E. Timmermans, L. Willmann, and H.W. Wilschut — KVI, University of Groningen, Groningen, The Netherlands

Single-ion based optical clocks are currently the best candidates for a future time and frequency standard with their stability exceeding that of the current ¹³³Cs standard. In particular, the 7s ²S_1/2 (F=2, mF=0)-6d ²D_3/2 (F=0, mF=0) at 828 nm transition in ²²³Ra⁺ could be exploited as a robust atomic clock operating at a fractional frequency uncertainty of 10⁻¹⁷ since it exhibits no linear Zeeman and electric quadrupole shifts[1]. Laser spectroscopy of trapped ^209−214Ra⁺ yielded the hyperfine structure of the 6d ²D_3/2 state and isotope shift of the 6d ²D_3/2-7p ²P_1/2 transition, providing input for the design of a Ra⁺ clock. Application include the direct comparison of the clock frequencies via an optical fiber networks and an optical frequency comb to determine frequency shifts in the gravitational field, and the implementation in an improved earth-bound positioning system. The comparison of different ions species is of fundamental interest because of their specific dependence on possible changes of fundamental constants, e.g. the fine structure constant. The Ra⁺ clock transition is much more sensitive to dα/dt than e.g. the Al⁺ clock, and the shift would have the opposite sign than that of Hg⁺. [1] O.O. Versolato et al., Physical Review A 83 (4), 043829. [2] G.S. Giri et al., Phys. Rev. A 84, 020503(R) (2011)