A high-flux, adjustable, compact cold-atom source

TL;DR

This paper presents a compact, high-flux cold-atom source using a pyramid MOT with an adjustable aperture, optimized for portable quantum devices and space applications, achieving record atomic flux with low power consumption.

Contribution

The development of an adjustable aperture pyramid MOT that surpasses previous cold-atom sources in flux and is suitable for portable and space-based quantum technologies.

Findings

Achieved 2.0x10^10 atoms/s flux of 87-Rb

Flux remains high with halved optical power, reducing by only 26%

Optimized aperture size enhances atomic flux beyond existing sources

Abstract

Magneto-optical traps (MOTs) are widely used for laser cooling of atoms. We have developed a high-flux compact cold-atom source based on a pyramid MOT with a unique adjustable aperture that is highly suitable for portable quantum technology devices, including space-based experiments. The adjustability enabled an investigation into the previously unexplored impact of aperture size on the atomic flux, and optimisation of the aperture size allowed us to demonstrate a higher flux than any reported cold-atom sources that use a pyramid, LVIS, 3D-MOT or grating MOT. We achieved 2.0(1)x10^10 atoms/s of 87-Rb with a mean velocity of 32(1)m/s, FWHM of 27.6(9)m/s and divergence of 58(3)mrad. Halving the total optical power to 195mW caused only a 26% reduction of the flux, and a 33% decrease in mean velocity. Methods to further decrease the velocity as required have been identified. The low power consumption and small size make this design suitable for a wide range of cold-atom technologies.