Enhanced Magnetic Trap Loading for Atomic Strontium

TL;DR

This paper introduces a depumping laser technique to enhance the continuous loading of atomic strontium into magnetic traps, significantly increasing atom numbers and optimizing trap loading efficiency.

Contribution

The study demonstrates a novel laser depumping method that improves magnetic trap loading for strontium, supported by a rate equation model and analysis of optimal parameters.

Findings

Up to 65% increase in atom number for bosonic isotopes

Up to 30% increase for fermionic isotope

Good agreement between model and experimental data

Abstract

We report on a technique to improve the continuous loading of atomic strontium into a magnetic trap from a Magneto-Optical Trap (MOT). This is achieved by adding a depumping laser tuned to the 3P1 to 3S1 (688-nm) transition. The depumping laser increases atom number in the magnetic trap and subsequent cooling stages by up to 65 % for the bosonic isotopes and up to 30 % for the fermionic isotope of strontium. We optimize this trap loading strategy with respect to the 688-nm laser detuning, intensity, and beam size. To understand the results, we develop a one-dimensional rate equation model of the system, which is in good agreement with the data. We discuss the use of other transitions in strontium for accelerated trap loading and the application of the technique to other alkaline-earth-like atoms.