In this article, we report the measurement of collision-induced loss rate coefficients β_{Li,Rb} and β_{Rb,Li}, and also discuss means to significantly suppress such collision induced losses. We first describe our dual-species magneto-optical trap (MOT) that allows us to simultaneously trap > 5x10^8 7Li atoms loaded from a Zeeman slower and > 2x10^8 85Rb atoms loaded from a dispenser. We observe strong interspecies collision-induced losses in the MOTs which dramatically reduce the maximum atom number achievable in the MOTs. We measure the trap loss rate coefficients β_{Li,Rb} and β_{Rb,Li}, and, from a study of their dependence on the MOT parameters, determine the cause for the losses observed. Our results provide valuable insights into ultracold collisions between 7Li and 85Rb, guide our efforts to suppress collision induced losses, and also pave the way for the production of ultracold 7Li85Rb molecules.In this article, we report the measurement of collision-induced loss rate coefficients β_{Li,Rb} and β_{Rb,Li}, and also discuss means to significantly suppress such collision induced losses. We first describe our dual-species magneto-optical trap (MOT) that allows us to simultaneously trap > 5x10^8 7Li atoms loaded from a Zeeman slower and > 2x10^8 85Rb atoms loaded from a dispenser. We observe strong interspecies collision-induced losses in the MOTs which dramatically reduce the maximum atom number achievable in the MOTs. We measure the trap loss rate coefficients β_{Li,Rb} and β_{Rb,Li}, and, from a study of their dependence on the MOT parameters, determine the cause for the losses observed. Our results provide valuable insights into ultracold collisions between 7Li and 85Rb, guide our efforts to suppress collision induced losses, and also pave the way for the production of ultracold 7Li85Rb molecules.

arXiv:1306.5196Journal of Physics B Atomic Molecular and Optical PhysicsMay 1, 201419 citations

An Optical Trap for $^{85}$ Rb and $^{87}$ RbAn Optical Trap for $^{85}$Rb and $^{87}$Rb

Juan Miguel Rey Pino, Scott B. Papp, Carl Wieman

Bulletin of the American Physical SocietyMay 18, 20050 citations

Continuous loading of a magneto-optical trap of Rb using a narrow transition

Rajnandan Choudhury Das, Thilagaraj Ravi, Samir Khan +1 more

We report continuous loading of $^{\text{87}}\mathrm{Rb}$ atoms in a magneto-optical trap (MOT) at narrow linewidth, 420-nm $5{S}_{1/2}$ , $F=2\ensuremath{\rightarrow}6{P}_{3/2}$, $F=3$ blue transition (blue MOT). Continuous loading of the blue MOT is achieved by superimposing the blue laser beam inside a hollow core of infrared (IR) laser beam driving the broad $5{S}_{1/2}$ , $F=2\ensuremath{\rightarrow}5{P}_{3/2}$, $F=3$ transition at 780 nm. We typically load $\ensuremath{\sim}{10}^{8}$ atoms in the blue MOT in 2.5 s. We characterize the continuous loading of the blue MOT with various parameters such as magnetic-field gradient, detuning, power and diameter of the blue MOT beam, and diameter of the hollow core (spot) inside the IR MOT beam. We observe that the blue laser beam should overfill the spot of the IR laser beam. This is because the blue laser cools the atoms to a lower temperature even in the presence of the broad IR laser, i.e., in the overlapped region, and hence helps in loading. To support the experimental result, we also present the theoretical framework for cooling atoms in the presence of two lasers driving two different transitions simultaneously. This method of continuous loading of the blue MOT can be useful to produce a continuous atomic beam of cold Rb atoms.We report continuous loading of $^{\text{87}}\mathrm{Rb}$ atoms in a magneto-optical trap (MOT) at narrow linewidth, 420-nm $5{S}_{1/2}$, $F=2\ensuremath{\rightarrow}6{P}_{3/2}$, $F=3$ blue transition (blue MOT). Continuous loading of the blue MOT is achieved by superimposing the blue laser beam inside a hollow core of infrared (IR) laser beam driving the broad $5{S}_{1/2}$, $F=2\ensuremath{\rightarrow}5{P}_{3/2}$, $F=3$ transition at 780 nm. We typically load $\ensuremath{\sim}{10}^{8}$ atoms in the blue MOT in 2.5 s. We characterize the continuous loading of the blue MOT with various parameters such as magnetic-field gradient, detuning, power and diameter of the blue MOT beam, and diameter of the hollow core (spot) inside the IR MOT beam. We observe that the blue laser beam should overfill the spot of the IR laser beam. This is because the blue laser cools the atoms to a lower temperature even in the presence of the broad IR laser, i.e., in the overlapped region, and hence helps in loading. To support the experimental result, we also present the theoretical framework for cooling atoms in the presence of two lasers driving two different transitions simultaneously. This method of continuous loading of the blue MOT can be useful to produce a continuous atomic beam of cold Rb atoms.

arXiv:2401.08286Physical Review AJun 10, 20247 citations

Limitations to the Number of $^{85}$ Rb and $^{87}$ Rb Atoms Simultaneously Confined in a Shallow Optical Trap.Limitations to the Number of $^{85}$Rb and $^{87}$Rb Atoms Simultaneously Confined in a Shallow Optical Trap.

Anthony Gorges, Mathew Hamilton, Jacob Roberts

Bulletin of the American Physical SocietyMay 20, 20090 citations

Ultrahigh vacuum pressure measurement using magneto-optical trap on atom chip

S. Supakar, Vivek Singh, Vibhuti Bhushan Tiwari +1 more

In this work, the UHV background pressure as low as 1.1×10−10 Torr has been measured using the loss rate characteristics of a vapor-loaded magneto-optical trap (MOT) formed on an atom chip in a UHV chamber. The loss rate due to non-rubidium (Rb) gases in the background in the chamber has been estimated by operating the MOT in low cooling beam intensities and low Rb pressure regimes simultaneously. Using this approach, we minimized the contributions of the intra-trap collisions as well as background MOT species collisions to the measured trap loss rate in our setup. These results can be useful for development of cold-atom based UHV pressure standards.In this work, the UHV background pressure as low as 1.1×10−10 Torr has been measured using the loss rate characteristics of a vapor-loaded magneto-optical trap (MOT) formed on an atom chip in a UHV chamber. The loss rate due to non-rubidium (Rb) gases in the background in the chamber has been estimated by operating the MOT in low cooling beam intensities and low Rb pressure regimes simultaneously. Using this approach, we minimized the contributions of the intra-trap collisions as well as background MOT species collisions to the measured trap loss rate in our setup. These results can be useful for development of cold-atom based UHV pressure standards.

Journal of Applied PhysicsJul 10, 20236 citations

Simultaneous Loading of

^{87}

Rb and

^{85}

Rb into a Optical Trap from a MOT

An Optical Trap for

^{85}

Rb and

^{87}

We report continuous loading of

^{\text{87}}\mathrm{Rb}

atoms in a magneto-optical trap (MOT) at narrow linewidth, 420-nm

5{S}_{1/2}

, $F=2\ensuremath{\rightarrow}6{P}_{3/2}$,

F=3

blue transition (blue MOT). Continuous loading of the blue MOT is achieved by superimposing the blue laser beam inside a hollow core of infrared (IR) laser beam driving the broad

5{S}_{1/2}

, $F=2\ensuremath{\rightarrow}5{P}_{3/2}$,

F=3

transition at 780 nm. We typically load $\ensuremath{\sim}{10}^{8}$ atoms in the blue MOT in 2.5 s. We characterize the continuous loading of the blue MOT with various parameters such as magnetic-field gradient, detuning, power and diameter of the blue MOT beam, and diameter of the hollow core (spot) inside the IR MOT beam. We observe that the blue laser beam should overfill the spot of the IR laser beam. This is because the blue laser cools the atoms to a lower temperature even in the presence of the broad IR laser, i.e., in the overlapped region, and hence helps in loading. To support the experimental result, we also present the theoretical framework for cooling atoms in the presence of two lasers driving two different transitions simultaneously. This method of continuous loading of the blue MOT can be useful to produce a continuous atomic beam of cold Rb atoms.

Limitations to the Number of

^{85}

Rb and

^{87}

Rb Atoms Simultaneously Confined in a Shallow Optical Trap.