Closed shell ions like Na+, as well as many molecular ions, cannot be easily laser cooled, for spectroscopy, quantum gates, and near zero-K reaction studies. We report on experiments studying collisions between trapped ions and trapped cold atoms. The ion-atom interaction is dominated by long-range polarization forces, principally a term V $\sim -\alpha $ /R $^{4}$ , $\alpha $ being the dipole polarizability of the neutral. The Hybrid trap consists of a linear Paul ion trap, set to trap Na+ ions, centered on a sodium magneto-optical trap (MOT). We investigate the sympathetic cooling of the (equal atomic mass) Na+ ion cloud concentric with the MOT, using either the 3s F=2$\to $3p F$ ^{\prime} $=3 or the 3s F=2$ \to $3p F$ ^{\prime}$= 2 MOT transitions. The lifetime of the ions in the Paul trap is observed to be detectably longer when they are sympathetically cooled by the cold neutral MOT atoms, consistent with simulations via SIMION.Closed shell ions like Na+, as well as many molecular ions, cannot be easily laser cooled, for spectroscopy, quantum gates, and near zero-K reaction studies. We report on experiments studying collisions between trapped ions and trapped cold atoms. The ion-atom interaction is dominated by long-range polarization forces, principally a term V $\sim -\alpha $ /R$^{4}$, $\alpha $ being the dipole polarizability of the neutral. The Hybrid trap consists of a linear Paul ion trap, set to trap Na+ ions, centered on a sodium magneto-optical trap (MOT). We investigate the sympathetic cooling of the (equal atomic mass) Na+ ion cloud concentric with the MOT, using either the 3s F=2$\to $3p F$^{\prime}$=3 or the 3s F=2$\to $3p F$^{\prime}$= 2 MOT transitions. The lifetime of the ions in the Paul trap is observed to be detectably longer when they are sympathetically cooled by the cold neutral MOT atoms, consistent with simulations via SIMION.

Nov 18, 20110 citations

Chemical reactions between cold trapped Ba+ ions and neutral molecules in the gas phase

Bernhard Roth, David Offenberg, C. B. Zhang +1 more

Using a laser-cooled ion trapping apparatus, we have investigated laser-induced chemical reactions between cold trapped ${\mathrm{Ba}}^{+}$ ions and several neutral molecular gases at room temperature, ${\mathrm{O}}_{2}$ , $\mathrm{C}{\mathrm{O}}_{2}$ , and ${\mathrm{N}}_{2}\mathrm{O}$ , leading to the production of cold trapped $(\ensuremath{\approx}20\phantom{\rule{0.3em}{0ex}}\mathrm{mK})$ $\mathrm{Ba}{\mathrm{O}}^{+}$ ions. The $\mathrm{Ba}{\mathrm{O}}^{+}$ ions were converted back to ${\mathrm{Ba}}^{+}$ ions via reaction with room-temperature CO. Reaction rates were determined by employing molecular dynamics simulations. The cold mixed-species ion ensembles produced were used for studying the efficiency of sympathetic cooling, by variation of the ratio of laser-cooled to sympathetically cooled ion numbers. In one extreme case, 20 laser-cooled $^{138}\mathrm{Ba}^{+}$ ions were capable of maintaining the translational temperature of 120 sympathetically cooled barium isotopes $(^{135--137}\mathrm{Ba}^{+})$ and 430 $^{138}\mathrm{Ba}^{16}{\mathrm{O}}^{+}$ molecules at approximately $25\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$ .Using a laser-cooled ion trapping apparatus, we have investigated laser-induced chemical reactions between cold trapped ${\mathrm{Ba}}^{+}$ ions and several neutral molecular gases at room temperature, ${\mathrm{O}}_{2}$, $\mathrm{C}{\mathrm{O}}_{2}$, and ${\mathrm{N}}_{2}\mathrm{O}$, leading to the production of cold trapped $(\ensuremath{\approx}20\phantom{\rule{0.3em}{0ex}}\mathrm{mK})$ $\mathrm{Ba}{\mathrm{O}}^{+}$ ions. The $\mathrm{Ba}{\mathrm{O}}^{+}$ ions were converted back to ${\mathrm{Ba}}^{+}$ ions via reaction with room-temperature CO. Reaction rates were determined by employing molecular dynamics simulations. The cold mixed-species ion ensembles produced were used for studying the efficiency of sympathetic cooling, by variation of the ratio of laser-cooled to sympathetically cooled ion numbers. In one extreme case, 20 laser-cooled $^{138}\mathrm{Ba}^{+}$ ions were capable of maintaining the translational temperature of 120 sympathetically cooled barium isotopes $(^{135--137}\mathrm{Ba}^{+})$ and 430 $^{138}\mathrm{Ba}^{16}{\mathrm{O}}^{+}$ molecules at approximately $25\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$.

Physical Review AOct 24, 200828 citations

Trapped ion system for sympathetic cooling and non-equilibrium dynamics

Charlie Doret, Sierra Jubin, Sarah Stevenson

Bulletin of the American Physical SocietyJun 6, 20170 citations

Efficient Sympathetic Cooling of Trapped Atomic Ions

Grahame Vittorini, Craig Robert Clark, Kenneth R. Brown

Bulletin of the American Physical SocietyJun 16, 20110 citations

^{4}

, $\alpha $ being the dipole polarizability of the neutral. The Hybrid trap consists of a linear Paul ion trap, set to trap Na+ ions, centered on a sodium magneto-optical trap (MOT). We investigate the sympathetic cooling of the (equal atomic mass) Na+ ion cloud concentric with the MOT, using either the 3s F=2$\to

3p F

^{\prime}

=3 or the 3s F=2

\to

3p F

^{\prime}$= 2 MOT transitions. The lifetime of the ions in the Paul trap is observed to be detectably longer when they are sympathetically cooled by the cold neutral MOT atoms, consistent with simulations via SIMION.

Using a laser-cooled ion trapping apparatus, we have investigated laser-induced chemical reactions between cold trapped

{\mathrm{Ba}}^{+}

ions and several neutral molecular gases at room temperature,

{\mathrm{O}}_{2}

\mathrm{C}{\mathrm{O}}_{2}

, and

{\mathrm{N}}_{2}\mathrm{O}

, leading to the production of cold trapped $(\ensuremath{\approx}20\phantom{\rule{0.3em}{0ex}}\mathrm{mK})$

\mathrm{Ba}{\mathrm{O}}^{+}

ions. The

\mathrm{Ba}{\mathrm{O}}^{+}

ions were converted back to

{\mathrm{Ba}}^{+}

ions via reaction with room-temperature CO. Reaction rates were determined by employing molecular dynamics simulations. The cold mixed-species ion ensembles produced were used for studying the efficiency of sympathetic cooling, by variation of the ratio of laser-cooled to sympathetically cooled ion numbers. In one extreme case, 20 laser-cooled

^{138}\mathrm{Ba}^{+}

ions were capable of maintaining the translational temperature of 120 sympathetically cooled barium isotopes

(^{135--137}\mathrm{Ba}^{+})

and 430

^{138}\mathrm{Ba}^{16}{\mathrm{O}}^{+}

molecules at approximately

25\phantom{\rule{0.3em}{0ex}}\mathrm{mK}