Rapid all-optical loading of trapped ions using a miniaturised atom source
POSTER
Abstract
In this poster I will discuss high-rate ion-loading in an RF trap using a novel atom source which uses low-power continuous-wave laser heating to produce a collimated thermal beam of loadable atoms.
Ion loading is the first step for many fundamental science and quantum information applications, but suffers from technical challenges. Resistively heated sources produce a relatively low velocity thermal atom beam, but the watt-level operating power disturbs the trap and makes integration in cryogenic systems challenging. Ablation loading of ions requires low power, but is highly sensitive to laser pulse parameters and gives rise to a high-velocity plume of atoms which are challenging to trap reliably. Finally, loading via pre-cooled atoms injected from a 2D MOT offers good performance, but comes at the cost of the significant increase in complexity, size and cost.
The source I will present uses a CW laser to heat the source metal held in a thermally isolated crucible. As such, it produces a thermal atom beam, which has been shown to lead to effective loading in both deep 3D traps and shallow surface traps. The source is engineered to be very thermally efficient, requiring a fraction of the power of resistively-heated sources in operation. The source is ~5 mm in scale, making it suitable for integration in the most compact vacuum systems. It also includes an integrated flux collimator, which increases the fraction of emitted atoms passing through the loading region, reducing the impact on the trap environment and improving lifetime.
I will present results of evaluating the source performance in a large linear RF ‘rod’ trap. I will present fluorescence measurements on the neutral atom flux to determine the atom density in the trap centre, the beam collimation, and the source metal temperature vs heating power. I will then show the source performance over a wider range of heating powers using ion loading-rate measurements. I will show that one ion can be loaded every 30 seconds with only 41.4(4) mW, and, in the higher end of the heating range, I demonstrate a loading rate of 24(3) s-1 with less than 84 mW. This is the highest reported rate with thermal sources to date. By investigating the effect of second-stage photo-ionisation laser power on the loading, I identify a future path to achieving average ion loading times below 1 ms.
Ion loading is the first step for many fundamental science and quantum information applications, but suffers from technical challenges. Resistively heated sources produce a relatively low velocity thermal atom beam, but the watt-level operating power disturbs the trap and makes integration in cryogenic systems challenging. Ablation loading of ions requires low power, but is highly sensitive to laser pulse parameters and gives rise to a high-velocity plume of atoms which are challenging to trap reliably. Finally, loading via pre-cooled atoms injected from a 2D MOT offers good performance, but comes at the cost of the significant increase in complexity, size and cost.
The source I will present uses a CW laser to heat the source metal held in a thermally isolated crucible. As such, it produces a thermal atom beam, which has been shown to lead to effective loading in both deep 3D traps and shallow surface traps. The source is engineered to be very thermally efficient, requiring a fraction of the power of resistively-heated sources in operation. The source is ~5 mm in scale, making it suitable for integration in the most compact vacuum systems. It also includes an integrated flux collimator, which increases the fraction of emitted atoms passing through the loading region, reducing the impact on the trap environment and improving lifetime.
I will present results of evaluating the source performance in a large linear RF ‘rod’ trap. I will present fluorescence measurements on the neutral atom flux to determine the atom density in the trap centre, the beam collimation, and the source metal temperature vs heating power. I will then show the source performance over a wider range of heating powers using ion loading-rate measurements. I will show that one ion can be loaded every 30 seconds with only 41.4(4) mW, and, in the higher end of the heating range, I demonstrate a loading rate of 24(3) s-1 with less than 84 mW. This is the highest reported rate with thermal sources to date. By investigating the effect of second-stage photo-ionisation laser power on the loading, I identify a future path to achieving average ion loading times below 1 ms.
Publication: pre-print of this work available arXiv:2512.10514 . The paper has been submitted for review to Physics Review Applied.
Presenters
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Lorenzo Versini
- University of Oxford