We report on the isotope-selective manipulation of Ca + using the laser-heating and laser-cooling techniques in a linear Paul trap. Only 40 Ca + was selectively laser-heated using the optical isotope shift and eliminated from the trap while keeping the target isotope in the trap. The elimination process of the dominant isotope 40 Ca + was investigated and 42, 43, 44, 48 Ca + in the natural isotope mixture of Ca + generated by laser ablation were successfully observed by means of applying the appropriate dc voltage on the end-cap electrodes without changing the laser frequencies, the laser powers and the duration of the laser irradiation. This simplified method enables us to efficiently laser-cool the rare isotopes.We report on the isotope-selective manipulation of Ca + using the laser-heating and laser-cooling techniques in a linear Paul trap. Only 40 Ca + was selectively laser-heated using the optical isotope shift and eliminated from the trap while keeping the target isotope in the trap. The elimination process of the dominant isotope 40 Ca + was investigated and 42, 43, 44, 48 Ca + in the natural isotope mixture of Ca + generated by laser ablation were successfully observed by means of applying the appropriate dc voltage on the end-cap electrodes without changing the laser frequencies, the laser powers and the duration of the laser irradiation. This simplified method enables us to efficiently laser-cool the rare isotopes.

Journal of Physics B Atomic Molecular and Optical PhysicsAug 8, 20129 citations

Isotope-selective photoionization for calcium ion trapping

D. Lucas, A. Ramos, Jonathan Home +6 more

We present studies of resonance-enhanced photoionization for isotope-selective loading of ${\mathrm{Ca}}^{+}$ into a Paul trap. The ${4s}^{2}{}^{1}{S}_{0}\ensuremath{\leftrightarrow}4s4p{}^{1}{P}_{1}$ transition of neutral calcium is driven by a 423 nm laser and the atoms are photoionized by a second laser at 389 nm. Isotope selectivity is achieved by using crossed atomic and laser beams to reduce the Doppler width significantly below the isotope shifts in the 423 nm transition. The loading rate of ions into the trap is studied under a range of experimental parameters for the abundant isotope ${}^{40}{\mathrm{Ca}}^{+}.$ Using the fluorescence of the atomic beam at 423 nm as a measure of the Ca number density, we estimate a lower limit for the absolute photoionization cross section of 170(60) Mb. We achieve loading and laser cooling of all the naturally occurring isotopes, without the need for enriched sources. Laser heating/cooling is observed to enhance the isotope selectivity. In the case of the rare species ${}^{43}{\mathrm{Ca}}^{+}$ and ${}^{46}{\mathrm{Ca}}^{+},$ which have not previously been laser cooled, the loading is not fully isotope selective, but we show that pure crystals of ${}^{43}{\mathrm{Ca}}^{+}$ may nevertheless be obtained. We find that for loading ${}^{40}{\mathrm{Ca}}^{+}$ the 389 nm laser may be replaced by an incoherent source.We present studies of resonance-enhanced photoionization for isotope-selective loading of ${\mathrm{Ca}}^{+}$ into a Paul trap. The ${4s}^{2}{}^{1}{S}_{0}\ensuremath{\leftrightarrow}4s4p{}^{1}{P}_{1}$ transition of neutral calcium is driven by a 423 nm laser and the atoms are photoionized by a second laser at 389 nm. Isotope selectivity is achieved by using crossed atomic and laser beams to reduce the Doppler width significantly below the isotope shifts in the 423 nm transition. The loading rate of ions into the trap is studied under a range of experimental parameters for the abundant isotope ${}^{40}{\mathrm{Ca}}^{+}.$ Using the fluorescence of the atomic beam at 423 nm as a measure of the Ca number density, we estimate a lower limit for the absolute photoionization cross section of 170(60) Mb. We achieve loading and laser cooling of all the naturally occurring isotopes, without the need for enriched sources. Laser heating/cooling is observed to enhance the isotope selectivity. In the case of the rare species ${}^{43}{\mathrm{Ca}}^{+}$ and ${}^{46}{\mathrm{Ca}}^{+},$ which have not previously been laser cooled, the loading is not fully isotope selective, but we show that pure crystals of ${}^{43}{\mathrm{Ca}}^{+}$ may nevertheless be obtained. We find that for loading ${}^{40}{\mathrm{Ca}}^{+}$ the 389 nm laser may be replaced by an incoherent source.

arXiv:physics/0310044Physical Review AJan 1, 2004163 citations

Laser cooling, trapping and spectroscopy of calcium isotopes

A. K. Mollema

Jan 1, 20082 citations

Selective loading and laser cooling of rare calcium isotope 43Ca+

U. Tanaka, I. Morita, S. Urabe

Applied Physics BOct 2, 200716 citations

We present studies of resonance-enhanced photoionization for isotope-selective loading of

{\mathrm{Ca}}^{+}

into a Paul trap. The ${4s}^{2}{}^{1}{S}_{0}\ensuremath{\leftrightarrow}4s4p{}^{1}{P}_{1}$ transition of neutral calcium is driven by a 423 nm laser and the atoms are photoionized by a second laser at 389 nm. Isotope selectivity is achieved by using crossed atomic and laser beams to reduce the Doppler width significantly below the isotope shifts in the 423 nm transition. The loading rate of ions into the trap is studied under a range of experimental parameters for the abundant isotope

{}^{40}{\mathrm{Ca}}^{+}.

Using the fluorescence of the atomic beam at 423 nm as a measure of the Ca number density, we estimate a lower limit for the absolute photoionization cross section of 170(60) Mb. We achieve loading and laser cooling of all the naturally occurring isotopes, without the need for enriched sources. Laser heating/cooling is observed to enhance the isotope selectivity. In the case of the rare species

{}^{43}{\mathrm{Ca}}^{+}

and

{}^{46}{\mathrm{Ca}}^{+},

which have not previously been laser cooled, the loading is not fully isotope selective, but we show that pure crystals of

{}^{43}{\mathrm{Ca}}^{+}

may nevertheless be obtained. We find that for loading

{}^{40}{\mathrm{Ca}}^{+}

the 389 nm laser may be replaced by an incoherent source.