Measurement of the 87Rb D-line vector tune-out wavelength

TL;DR

This paper presents a high-precision measurement of the vector tune-out wavelength for 87Rb using circularly polarized light, providing insights into atomic polarizability components and validating theoretical models.

Contribution

The study provides the first precise experimental determination of the vector tune-out wavelength for 87Rb with circular polarization, highlighting the influence of vector polarizability on atomic responses.

Findings

Measured tune-out wavelength: 785.1522(3) nm

Agreement with theoretical predictions considering core and off-resonant states

Demonstrated sensitivity of tune-out wavelength to vector polarizability components

Abstract

We report a precision measurement of a tune-out wavelength for 87Rb 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 $\sigma_-$ polarized light with an an estimated 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.