Chirped magneto-optical trap of molybdenum

TL;DR

This paper demonstrates a chirped magneto-optical trap for molybdenum atoms, enhancing atom capture efficiency and enabling detailed lifetime and isotope shift measurements, with implications for cooling other molecules like MgF.

Contribution

It introduces a chirped laser detuning technique to improve molybdenum atom trapping and provides precise isotope shift data, advancing atomic cooling methods.

Findings

Atom number increased by over twofold with chirped detuning.

Achieved 100 ms vacuum-limited lifetime in magnetic trap.

Provided improved isotope shift measurements for molybdenum transitions.

Abstract

We have directly loaded a cryogenic beam of molybdenum atoms into a magneto-optical trap. By chirping the detuning of the trapping lasers, we were able to enhance the number of atoms loaded into the trap by more than a factor of two. We optimize the trapped samples for atom number, temperature, and lifetime by varying the laser-cooling parameters. The laser-cooled molybdenum atoms are subsequently transferred to a magnetic trap where we achieve vacuum-limited lifetimes of 100\,ms. Comparison of magneto-optical trap and magnetic trap lifetimes allow us to extract partial decay rates of the $\text{z}\,^7\text{P}^\text{o}_4\rightarrow\text{a}\,^5\text{D}_4$ and $\text{z}\,^7\text{P}^\text{o}_4\rightarrow\text{a}\,^5\text{D}_3$ transitions. We also provide measurements of the isotope shifts for the $\text{a}\,^7\text{S}_3\rightarrow \text{z}\,^7\text{P}^\text{o}_4$ transition with up to four times better precision than previously reported. Finally, we discuss the prospect of applying the chriped magneto-optical trap to produce laser-cooled samples of MgF.