A steady-state magneto-optical trap of fermionic strontium on a narrow-line transition

TL;DR

This paper demonstrates a steady-state magneto-optical trap for fermionic strontium atoms on a narrow transition, achieving high atom numbers and low temperatures, crucial for continuous-wave superradiant lasers and optical clocks.

Contribution

The authors develop a steady-state MOT for fermionic strontium on a narrow transition, enabling continuous operation of superradiant lasers and optical clocks.

Findings

Achieved 8.4×10^7 atoms in the MOT

Loaded atoms at a rate of 1.3×10^7 atoms/sec

Achieved an average temperature of 12 μK

Abstract

A steady-state magneto-optical trap (MOT) of fermionic strontium atoms operating on the 7.5 kHz-wide ${^1\mathrm{S}_0} - {^3\mathrm{P}_1}$ transition is demonstrated. This MOT features $8.4 \times 10^{7}$ atoms, a loading rate of $1.3\times 10^{7}$atoms/s, and an average temperature of 12 $\mu$K. These parameters make it well suited to serve as a source of atoms for continuous-wave superradiant lasers operating on strontium's mHz-wide clock transition. Such lasers have only been demonstrated using pulsed Sr sources, limiting their range of applications. Our MOT makes an important step toward continuous operation of these devices, paving the way for continuous-wave active optical clocks.