A steady-state magneto-optical trap with 100 fold improved phase-space density

TL;DR

This paper reports a steady-state strontium magneto-optical trap with a 100-fold increase in phase-space density, achieved through a hybrid cooling approach, enabling advanced quantum applications like continuous atom lasers and high-precision clocks.

Contribution

The authors demonstrate a high phase-space density steady-state MOT for strontium using a novel hybrid cooling scheme, significantly surpassing previous densities.

Findings

Achieved a steady-state phase-space density of 1.3×10^{-3}.

Implemented a hybrid slower+MOT configuration for efficient cooling.

Produced a Bose-Einstein condensate at the MOT location.

Abstract

We demonstrate a continuously loaded $^{88}\mathrm{Sr}$ magneto-optical trap (MOT) with a steady-state phase-space density of $1.3(2) \times 10^{-3}$. This is two orders of magnitude higher than reported in previous steady-state MOTs. Our approach is to flow atoms through a series of spatially separated laser cooling stages before capturing them in a MOT operated on the 7.4-kHz linewidth Sr intercombination line using a hybrid slower+MOT configuration. We also demonstrate producing a Bose-Einstein condensate at the MOT location, despite the presence of laser cooling light on resonance with the 30-MHz linewidth transition used to initially slow atoms in a separate chamber. Our steady-state high phase-space density MOT is an excellent starting point for a continuous atom laser and dead-time free atom interferometers or clocks.