arXiv:2201.10435 · Physical Review A
Measurement of the Rb87 D -line vector tune-out wavelength
Adam Fallon, Edward Moan, E. A. Larson, Charles A. Sackett
Abstract
We report a precision measurement of a tune-out wavelength for $^{87}\mathrm{Rb}$ using circularly polarized light. A tune-out wavelength characterizes a zero in the electric polarizability of the atom. For circularly polarized light, the total polarizability depends on both the scalar and vector polarizability components. This shifts the location of the tune-out wavelength and makes it sensitive to different combinations of atomic dipole matrix elements than the scalar polarizability alone. Using ${\ensuremath{\sigma}}_{\ensuremath{-}}$ polarized light with a purity of 0.9931(1), we observe a tune-out wavelength of 785.1522(3) nm, which agrees with theoretical expectations when small contributions from the core electrons and off-resonant valence states are taken into account.