Two-tone Doppler cooling of radial two-dimensional crystals in a radiofrequency ion trap

Abstract

We study the Doppler-cooling of radial two-dimensional (2D) Coulomb crystals of trapped barium ions in a radiofrequency trap. Ions in radial 2D crystals experience micromotion of an amplitude that increases linearly with the distance from the trap center, leading to a position-dependent frequency modulation of laser light in each ion's rest frame. We use two tones of Doppler-cooling laser light separated by approximately 100~MHz to efficiently cool distinct regions in the crystals with differing amplitudes of micromotion. This technique allows us to trap and cool more than 50 ions populating 4 shells in a radial two-dimensional crystal, where with a single tone of Doppler cooling light we are limited to 30 ions in 3 shells. We also individually characterize the micromotion of all ions within the crystals, and use this information to locate the center of the trap and to determine the Matthieu parameters $q_x$ and $q_y$.

7 Pages, 5 Figures

References in corpus (8)

• Quantum-enhanced sensing of displacements and electric fields with large trapped-ion crystals
• Imaging and time stamping of photons with nanosecond resolution in Timepix based optical cameras
• Modes of Oscillation in Radiofrequency Paul Traps
• Precise Experimental Investigation of Eigenmodes in a Planar Ion Crystal
• High Speed Imaging of Spectral-Temporal Correlations in Hong-Ou-Mandel Interference
• Quantum Computation under Micromotion in a Planar Ion Crystal
• Engineering spin-spin interactions with optical tweezers in trapped ions
• An open-endcap blade trap for radial-2D ion crystals

Cited by in corpus (6)

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• Individually Addressed Entangling Gates in a Two-Dimensional Ion Crystal
• Efficient site-resolved imaging and spin-state detection in dynamic two-dimensional ion crystals
• Micromotion-Synchronized Pulsed Doppler Cooling of Trapped Ions
• Study of afterpulsing in optical image intensifiers