Ionic crystals in a linear Paul trap

Author :M. G. Raizen, J. M. Gilligan, J. C. Bergquist, W. M. Itano, and D. J. Wineland
Publication :Physical Review A
Volume :45
Number :9
Pages :6493-6501
Year :1992

We describe a configuration for a linear Paul rf ion trap. This trap can store a long string of ions with a small second-order Doppler shift, comparable to that achieved with a single ion in a quadrupole Paul trap. Crystallized strings of trapped ions, as well as more complicated structures, have been observed in the trap. We report an observation of the 40.5-GHz ground-state hyperfine interval of 199Hg+ by microwave-optical double-resonance spectroscopy and discuss prospects for a microwave frequency standard based on a trapped string of ions.