Precision Measurement of the 87-Rb Tune-Out Wavelength in the Hyperfine Ground State F=1 at 790 nm

TL;DR

This paper reports a highly precise measurement of the 87-Rb tune-out wavelength at 790 nm, revealing subtle atomic effects and providing insights beyond simple two-level models.

Contribution

The study provides the first sub-picometer accuracy measurement of the 87-Rb tune-out wavelength and investigates vector and tensor Stark shifts, enhancing atomic physics understanding.

Findings

Measured the tune-out wavelength to 790.01858(23) nm with sub pm accuracy.

Quantified contributions from vector and tensor Stark shifts.

Compared results with theory to reveal inner shell effects.

Abstract

We report on a precision measurement of the $D$ line tune-out wavelength of $^{87}$Rubidium in the hyperfine ground state $|F=1, m_F=0,\pm1 \rangle$ manifold at 790 nm, where the scalar ac Stark shifts of the $D_1$ and the $D_2$ lines cancel. This wavelength is sensitive to usually neglected contributions from vector and tensor ac Stark shifts, transitions to higher principle quantum numbers, and core electrons. The ac Stark shift is probed by Kapitza-Dirac scattering of a Rubidium Bose-Einstein condensate in a one-dimensional optical lattice in free space and controlled magnetic environment. The tune-out wavelength of the magnetically insensitive $m_F=0$ state was determined to 790.01858(23) nm with sub pm accuracy. An in situ absolute polarization, and magnetic background field measurement is performed by employing the ac vector Stark shift for the $m_F=\pm 1$ states. Comparing our findings to theory, we get quantitative insight into atomic physics beyond commonly used two-level atom approximations or the neglect of inner shell contributions.