Mode shaping in mixed ion crystals of 40Ca2+ and 40Ca+


We present studies of mixed Coulomb crystals of 40Ca+ and 40Ca2+ ions in a linear Paul trap. Doubly charged ions are produced by photoionization of trapped 40Ca+ with a vacuum ultraviolet laser source and sympathetically cooled via Doppler cooled 40Ca+ ions. We investigate experimentally and theoretically the structural configurations and the vibrational modes of these mixed crystals. Our results with 40Ca2+ are an important step towards experimental realization of the proposals for mode shaping in a linear crystal and spin-dependent configuration changes from zigzag to linear as proposed by Li et al. (Phys Rev A 87:052304, 2013) and Li and Lesanovsky (Phys Rev Lett 108:023003, 2012) using ions excited to Rydberg states.

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We thank Weibin Li, Alexander Glaetzle, Rejish Nath, Igor Lesanovsky and Peter Zoller for helpful discussions. Further, we thank Julian Naber for earlier contributions to the experiment. We acknowledge financial support by the EU Chist-Era Project R-Ion and by the BMBF.

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Correspondence to T. Feldker.

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Feldker, T., Pelzer, L., Stappel, M. et al. Mode shaping in mixed ion crystals of 40Ca2+ and 40Ca+ . Appl. Phys. B 114, 11–16 (2014).

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  • Mode Shaping
  • Rydberg State
  • Radial Mode
  • Trapping Frequency
  • Linear String