High-Flux Cold Ytterbium Atomic Beam Source Using Two-dimensional Laser Cooling with Intercombination Transition

We demonstrate a slow ytterbium atomic beam with a tunable longitudinal velocity in the range of $20$-$30\ \mathrm{m/s}$, a transverse temperature of $11\ \mathrm{\mu K}$, and flux of up to $1.2 \times 10^{9}\ \mathrm{atoms/s}$. Such performance is realized by applying two-dimensional cooling, with an intercombination transition, to a slow atomic beam generated by a dipolar-allowed transition. We also discuss the feasibility of narrowing the transverse momentum width to less than the recoil momentum using the velocity-selective optical transition of atoms based on a long-lived metastable state. Such a high-flux atomic beam will be a powerful tool for constructing compact and continuous Bragg diffraction interferometers with ytterbium atoms.Comment: 7 pages, 7 figure