Loading of atoms into an optical trap with high initial phase-space density

TL;DR

This paper presents a novel method for loading cold rubidium atoms into an optical trap with significantly higher initial phase-space density than traditional methods, enhancing the efficiency of quantum gas creation.

Contribution

The authors introduce a new loading technique using optimized optical molasses with large detuning, achieving higher initial PSD in optical traps compared to conventional MOT loading.

Findings

Loaded over 3 million rubidium atoms with temperatures below 20 μK.

Achieved initial PSD of 1.1 x 10^{-3}, surpassing conventional methods by 1-2 orders of magnitude.

Method is promising for rapid quantum gas production with large atom numbers.

Abstract

We report a method for loading cold atoms into an optical trap with high initial phase-space density (PSD). When the trap beam is overlapped with atoms in optical molasses of optimized parameters including large cooling beam detuning compared with conventional detuning used for a magneto-optical trap (MOT), more than $3 \times 10^6$ rubidium atoms with an initial temperature less than 20 $\mu$K are loaded into a single beam trap. The obtained maximum initial PSD is estimated to be $1.1 \times 10^{-3}$, which is one or two orders of magnitude greater than that achieved with the conventional loading into an optical trap from atoms in a MOT. The proposed method is promising for creating a quantum gas with a large number of atoms in a short evaporation time.