Two-color photoassociation spectroscopy of ytterbium atoms and the precise determinations of s-wave scattering lengths

TL;DR

This study uses high-resolution two-color photoassociation spectroscopy to accurately measure binding energies of ytterbium dimers, enabling precise calculation of s-wave scattering lengths and van der Waals coefficients for multiple isotopes.

Contribution

It provides the first precise experimental determination of s-wave scattering lengths for all pairs of stable ytterbium isotopes, validated by theoretical calculations.

Findings

Measured binding energies of ytterbium dimers across six isotopes.

Calculated s-wave scattering lengths with high precision for all isotope pairs.

Determined the van der Waals coefficient C_6 for Yb_2 molecules.

Abstract

By performing high-resolution two-color photoassociation spectroscopy, we have successfully determined the binding energies of several of the last bound states of the homonuclear dimers of six different isotopes of ytterbium. These spectroscopic data are in excellent agreement with theoretical calculations based on a simple model potential, which very precisely predicts the s-wave scattering lengths of all 28 pairs of the seven stable isotopes. The s-wave scattering lengths for collision of two atoms of the same isotopic species are 13.33(18) nm for ^{168}Yb, 3.38(11) nm for ^{170}Yb, -0.15(19) nm for ^{171}Yb, -31.7(3.4) nm for ^{172}Yb, 10.55(11) nm for ^{173}Yb, 5.55(8) nm for ^{174}Yb, and -1.28(23) nm for ^{176}Yb. The coefficient of the lead term of the long-range van der Waals potential of the Yb_2 molecule is C_6=1932(30) atomic units $(E_h a_0^6 \approx 9.573\times 10^{-26}$ J nm^6).