By tightly focusing a far off-resonance laser beam, we can form an optical dipole trap with large... more By tightly focusing a far off-resonance laser beam, we can form an optical dipole trap with large oscillation frequencies. Such systems are desirable both for applications in quantum information processing [1] and for investigating quantum mechanics at the single event limit [2]. Our setup is based on the atomic tweezers concept, in which an objective lens is used both to focus the trapping beam, and to image the fluorescence from the trapped atoms. In this talk I will describe our experimental setup and present our recent results on efficient detection and imaging of dense samples of Rb85 atoms in the micro-trap. We address imaging issues resulting from the multi-level structure of the atoms, the different shifts to the various internal states induced by the trapping beam and various loss mechanisms associated with the on-resonance detection process. Detailed understanding of the in-situ detection processes may allow for loss-free, number counting of the trapped atoms. [1] A. Ga"etan et. al. Nature Physics 5, 115 - 118 (2009); E. Urban et. al., Nature Physics 5, 110 - 114 (2009). [2] Th. Sauter et. al., Phys. Rev. Lett. 57, 1696 - 1698 (1986).
2011 International Quantum Electronics Conference (IQEC) and Conference on Lasers and Electro-Optics (CLEO) Pacific Rim, 2011
The fact that a single neutral atom stored in an optical micro-trap is very well isolated from th... more The fact that a single neutral atom stored in an optical micro-trap is very well isolated from the environment makes it attractive for application in a quantum logic device. Scaling such a device requires a consistent and efficient method of loading a single atom into the micro-trap. By inducing light-assisted collisions between trapped pairs of atoms we observe the outcome of individual collision events. This allowed us to devise a method that enables a loading efficiency of 83% of a single atom into a micro-trap. Furthermore, we are able to accurately count the small number of atoms using fluorescence imaging at high densities while minimizing loss through light assisted collisions.
We report on a directional atomic beam created using an alkali metal dispenser and a nozzle. By a... more We report on a directional atomic beam created using an alkali metal dispenser and a nozzle. By applying a high current (15 A) pulse to the dispenser at room temperature we can rapidly heat it to a temperature at which it starts dispensing, avoiding the need for preheating. The atomic beam produced is capable of loading 90% of a magneto-optical trap (MOT) in less than 7 s while maintaining a low vacuum pressure of <10(-11) Torr. The transverse velocity components of the atomic beam are measured to be within typical capture velocities of a rubidium MOT. Finally, we show that the atomic beam can be turned off within 1.8 s.
ABSTRACT Within the combined potential of an optical lattice and a harmonic magnetic trap, it is ... more ABSTRACT Within the combined potential of an optical lattice and a harmonic magnetic trap, it is possible to form matter wave packets by intensity modulation of the lattice. An analysis of the production and motion of these wave packets provides a detailed understanding of the dynamical evolution of the system. The modulation technique also allows for a controllable transfer (de-excitation) of atoms from such wave packets to a state bound by the lattice. Thus, it acts as a beam splitter for matter waves that can selectively address different bands, enabling the preparation of atoms in selected localized states. The combination of wave packet creation and de-excitation closely resembles the well-known method of pump-probe spectroscopy. Here, we use the de-excitation for precision spectroscopy of the anharmonicity of the magnetic trap. Finally, we demonstrate that lattice modulation can be used to excite matter wave packets to even higher momenta, producing fast wave packets with potential applications in precision measurements.
We investigate the dynamics of the atom-optics delta-kicked rotor in the vicinity of quantum reso... more We investigate the dynamics of the atom-optics delta-kicked rotor in the vicinity of quantum resonance. Although small deviations from resonant conditions lead to a negligible change in the momentum space probability density, they lead to a significant relative phase change between the different momentum states taking part in the dynamics. By adding a tailored pulse to the kicked rotor pulse
By tightly focusing a far off-resonance laser beam, we can form an optical dipole trap with large... more By tightly focusing a far off-resonance laser beam, we can form an optical dipole trap with large oscillation frequencies. Such systems are desirable both for applications in quantum information processing [1] and for investigating quantum mechanics at the single event limit [2]. Our setup is based on the atomic tweezers concept, in which an objective lens is used both to focus the trapping beam, and to image the fluorescence from the trapped atoms. In this talk I will describe our experimental setup and present our recent results on efficient detection and imaging of dense samples of Rb85 atoms in the micro-trap. We address imaging issues resulting from the multi-level structure of the atoms, the different shifts to the various internal states induced by the trapping beam and various loss mechanisms associated with the on-resonance detection process. Detailed understanding of the in-situ detection processes may allow for loss-free, number counting of the trapped atoms. [1] A. Ga"etan et. al. Nature Physics 5, 115 - 118 (2009); E. Urban et. al., Nature Physics 5, 110 - 114 (2009). [2] Th. Sauter et. al., Phys. Rev. Lett. 57, 1696 - 1698 (1986).
2011 International Quantum Electronics Conference (IQEC) and Conference on Lasers and Electro-Optics (CLEO) Pacific Rim, 2011
The fact that a single neutral atom stored in an optical micro-trap is very well isolated from th... more The fact that a single neutral atom stored in an optical micro-trap is very well isolated from the environment makes it attractive for application in a quantum logic device. Scaling such a device requires a consistent and efficient method of loading a single atom into the micro-trap. By inducing light-assisted collisions between trapped pairs of atoms we observe the outcome of individual collision events. This allowed us to devise a method that enables a loading efficiency of 83% of a single atom into a micro-trap. Furthermore, we are able to accurately count the small number of atoms using fluorescence imaging at high densities while minimizing loss through light assisted collisions.
We report on a directional atomic beam created using an alkali metal dispenser and a nozzle. By a... more We report on a directional atomic beam created using an alkali metal dispenser and a nozzle. By applying a high current (15 A) pulse to the dispenser at room temperature we can rapidly heat it to a temperature at which it starts dispensing, avoiding the need for preheating. The atomic beam produced is capable of loading 90% of a magneto-optical trap (MOT) in less than 7 s while maintaining a low vacuum pressure of <10(-11) Torr. The transverse velocity components of the atomic beam are measured to be within typical capture velocities of a rubidium MOT. Finally, we show that the atomic beam can be turned off within 1.8 s.
ABSTRACT Within the combined potential of an optical lattice and a harmonic magnetic trap, it is ... more ABSTRACT Within the combined potential of an optical lattice and a harmonic magnetic trap, it is possible to form matter wave packets by intensity modulation of the lattice. An analysis of the production and motion of these wave packets provides a detailed understanding of the dynamical evolution of the system. The modulation technique also allows for a controllable transfer (de-excitation) of atoms from such wave packets to a state bound by the lattice. Thus, it acts as a beam splitter for matter waves that can selectively address different bands, enabling the preparation of atoms in selected localized states. The combination of wave packet creation and de-excitation closely resembles the well-known method of pump-probe spectroscopy. Here, we use the de-excitation for precision spectroscopy of the anharmonicity of the magnetic trap. Finally, we demonstrate that lattice modulation can be used to excite matter wave packets to even higher momenta, producing fast wave packets with potential applications in precision measurements.
We investigate the dynamics of the atom-optics delta-kicked rotor in the vicinity of quantum reso... more We investigate the dynamics of the atom-optics delta-kicked rotor in the vicinity of quantum resonance. Although small deviations from resonant conditions lead to a negligible change in the momentum space probability density, they lead to a significant relative phase change between the different momentum states taking part in the dynamics. By adding a tailored pulse to the kicked rotor pulse
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Papers by Andrew Hilliard