Magneto-Optical Trap for Thulium Atoms

TL;DR

This paper demonstrates the successful creation of a magneto-optical trap for thulium atoms, achieving significant atom numbers and low temperatures, with insights into atomic lifetime influenced by optical leaks.

Contribution

It introduces a magneto-optical trapping method for thulium atoms using a 410 nm transition, including measurements of atom number, temperature, and leak rates.

Findings

Trapped up to 7×10^4 atoms at 0.8 mK

Atom lifetime varies between 0.3 and 1.5 seconds due to optical leaks

Repumping increases atom number and lifetime by 30%

Abstract

Thulium atoms are trapped in a magneto-optical trap using a strong transition at 410 nm with a small branching ratio. We trap up to $7\times10^{4}$ atoms at a temperature of 0.8(2) mK after deceleration in a 40 cm long Zeeman slower. Optical leaks from the cooling cycle influence the lifetime of atoms in the MOT which varies between 0.3 -1.5 s in our experiments. The lower limit for the leaking rate from the upper cooling level is measured to be 22(6) s$^{-1}$. The repumping laser transferring the atomic population out of the F=3 hyperfine ground-state sublevel gives a 30% increase for the lifetime and the number of atoms in the trap.