Trapping Single Ions and Coulomb Crystals with Light Fields

Michael Drewsen

K. Okada, Toshiyuki Takayanagi, M. Wada +2 more

Ion Coulomb crystals of laser-cooled ${\text{Ca}}^{+}$ ions have been observed in a cryogenic linear octupole rf ion trap for the first time. Due to the almost field-free central region, large ion crystals containing over ${10}^{4}$ ions of millimeter size were successfully produced. The shapes of the crystals can be manipulated by changing the static voltages applied to the octupole rods and the endcap electrodes. Quasi-two-dimensional Coulomb crystals consisting of a small number of ions were also observed with single-ion sensitivity. When a large number of ions is crystallized in the octupole trap, a new kind crystal image with a dip along the axial direction was obtained. The results show that a linear octupole trap and multipole traps are available for producing large, cold, and novel ion Coulomb crystals. The planar ring-type crystal which has not been observed before may lead to future interesting applications.

Leon Karpa

Leon Karpa

Peter F. Herskind, A. Mortensen, E.S. Nielsen +2 more

The authors report on the stored light in an ion Coulomb crystal coupled to a relatively low finesse optical resonator. A two-species ion Coulomb crystal is employed in a linear Paul trap, where the laser cooled heavier ion-component sympathetically cools the lighter ion-component.

Michael Drewsen

In this contribution, we present some of our recent results involving ion Coulomb crystals in linear Paul traps. A few results regarding single component crystals are discussed, but the main focus is on properties of two-component crystals and their applications in the fields of cold molecular physics and quantum optics.