We present a method for producing three-dimensional Bose-Einstein condensates using only laser cooling. The phase transition to condensation is crossed with 2.5×10^{4} ^{87}Rb atoms at a temperature of T_{c}=0.6 μK after 1.4 s of cooling. Atoms are trapped in a crossed optical dipole trap and cooled using Raman cooling with far-off-resonant optical pumping light to reduce atom loss and heating. The achieved temperatures are well below the effective recoil temperature. We find that during the final cooling stage at atomic densities above 10^{14} cm^{-3}, careful tuning of trap depth and optical-pumping rate is necessary to evade heating and loss mechanisms. The method may enable the fast production of quantum degenerate gases in a variety of systems including fermions.We present a method for producing three-dimensional Bose-Einstein condensates using only laser cooling. The phase transition to condensation is crossed with 2.5×10^{4} ^{87}Rb atoms at a temperature of T_{c}=0.6 μK after 1.4 s of cooling. Atoms are trapped in a crossed optical dipole trap and cooled using Raman cooling with far-off-resonant optical pumping light to reduce atom loss and heating. The achieved temperatures are well below the effective recoil temperature. We find that during the final cooling stage at atomic densities above 10^{14} cm^{-3}, careful tuning of trap depth and optical-pumping rate is necessary to evade heating and loss mechanisms. The method may enable the fast production of quantum degenerate gases in a variety of systems including fermions.

arXiv:1902.10361Physical Review LettersMay 24, 201982 citations

Sympathetic cooling of Rb + ions by cold Rb atoms in an ion-neutral hybrid trap

Shuangfei Lü, Feng-Dong Jia, Xiaokang Li +4 more

Sympathetic cooling of Rb+ ions by cold Rb atoms is studied in an ion-neutral hybrid trap. The effect of a linear Paul trap (LPT) parameter q1, 2 on the sympathetic cooling is studied by measuring the changes in ion number Ni and temperature Ti after interaction with cold atoms. The sympathetic cooling effect is observed with 0.3 ≤ |q1, 2| ≤ 0.8. At the |q1, 2| value of 0.32, ions are cooled from initial (2 010±380) K to (325±35) K and the lifetime of ions is extended from 7 s to 15 s via sympathetic cooling. These findings are very useful for cooling of atomic and molecular ions, especially for the ions without available optical channels.Sympathetic cooling of Rb+ ions by cold Rb atoms is studied in an ion-neutral hybrid trap. The effect of a linear Paul trap (LPT) parameter q1, 2 on the sympathetic cooling is studied by measuring the changes in ion number Ni and temperature Ti after interaction with cold atoms. The sympathetic cooling effect is observed with 0.3 ≤ |q1, 2| ≤ 0.8. At the |q1, 2| value of 0.32, ions are cooled from initial (2 010±380) K to (325±35) K and the lifetime of ions is extended from 7 s to 15 s via sympathetic cooling. These findings are very useful for cooling of atomic and molecular ions, especially for the ions without available optical channels.

Mar 15, 20180 citations

Double resonance spectroscopy of laser-cooled Rb atoms

Alastair G. Sinclair, Barry D. McDonald, Erling Riis +1 more

Optics CommunicationsMar 1, 199427 citations

Dynamics of cooled atoms under coherent population trapping conditions

Eugeny Korsunsky, Boris G. Matisov, Laurentius Windholz

Jan 1, 19930 citations

Cooling of trapped ions by resonant charge exchange

Sourav Dutta, S. A. Rangwala

The two most widely used ion cooling methods are laser cooling and sympathetic cooling by elastic collisions (ECs). Here, we demonstrate another method of cooling ions that is based on resonant charge exchange (RCE) between the trapped ion and the ultracold parent atom. Specifically, trapped $\mathrm{C}{\mathrm{s}}^{+}$ ions are cooled by collisions with cotrapped, ultracold Cs atoms and, separately, by collisions with cotrapped, ultracold Rb atoms. We observe that the cooling of $\mathrm{C}{\mathrm{s}}^{+}$ ions by Cs atoms is more efficient than the cooling of $\mathrm{C}{\mathrm{s}}^{+}$ ions by Rb atoms. This signals the presence of a cooling mechanism apart from the elastic ion-atom collision channel for the Cs- $\mathrm{C}{\mathrm{s}}^{+}$ case, which is cooling by RCE. The efficiency of cooling by RCE is experimentally determined and the per-collision cooling is found to be two orders of magnitude higher than cooling by EC. The result provides the experimental basis for future studies on charge transport by electron hopping in atom-ion hybrid systems.The two most widely used ion cooling methods are laser cooling and sympathetic cooling by elastic collisions (ECs). Here, we demonstrate another method of cooling ions that is based on resonant charge exchange (RCE) between the trapped ion and the ultracold parent atom. Specifically, trapped $\mathrm{C}{\mathrm{s}}^{+}$ ions are cooled by collisions with cotrapped, ultracold Cs atoms and, separately, by collisions with cotrapped, ultracold Rb atoms. We observe that the cooling of $\mathrm{C}{\mathrm{s}}^{+}$ ions by Cs atoms is more efficient than the cooling of $\mathrm{C}{\mathrm{s}}^{+}$ ions by Rb atoms. This signals the presence of a cooling mechanism apart from the elastic ion-atom collision channel for the Cs-$\mathrm{C}{\mathrm{s}}^{+}$ case, which is cooling by RCE. The efficiency of cooling by RCE is experimentally determined and the per-collision cooling is found to be two orders of magnitude higher than cooling by EC. The result provides the experimental basis for future studies on charge transport by electron hopping in atom-ion hybrid systems.

arXiv:1705.07572Physical Review AApr 6, 201822 citations

\mathrm{C}{\mathrm{s}}^{+}

ions are cooled by collisions with cotrapped, ultracold Cs atoms and, separately, by collisions with cotrapped, ultracold Rb atoms. We observe that the cooling of

\mathrm{C}{\mathrm{s}}^{+}

ions by Cs atoms is more efficient than the cooling of

\mathrm{C}{\mathrm{s}}^{+}

ions by Rb atoms. This signals the presence of a cooling mechanism apart from the elastic ion-atom collision channel for the Cs-

\mathrm{C}{\mathrm{s}}^{+}

case, which is cooling by RCE. The efficiency of cooling by RCE is experimentally determined and the per-collision cooling is found to be two orders of magnitude higher than cooling by EC. The result provides the experimental basis for future studies on charge transport by electron hopping in atom-ion hybrid systems.