# Measurement of a $^7$Li tune-out wavelength by phase-patterned atom interferometry

## TL;DR

This paper introduces a novel atom interferometry method that uses spatial phase patterning to precisely measure the $^7$Li tune-out wavelength, providing new insights into atomic polarizability near 671 nm.

## Contribution

The study demonstrates the first direct measurement of the $^7$Li tune-out wavelength using phase-patterned atom interferometry, enhancing precision in atomic property measurements.

## Key findings

- Measured the tensor-shifted tune-out wavelength as 3329.3(1.4) MHz.
- Measured the scalar polarizability tune-out wavelength as 3310.1(4.9) MHz.
- Introduced a technique for spatially resolved phase profile sensing.

## Abstract

Atom interferometers typically use the total populations the interferometer's output ports as the signal, but finer spatial structure can contain useful information. We pattern a matter-wave phase profile onto an atomic sample. An interferometer translates the phase into a measurable pattern in the atomic density that we use perform the first direct precision measurement of the $^7$Li tune-out wavelength near 671 nm. Expressed as a detuning from the $|2S_{1/2},F{=}2\rangle{\rightarrow}|2P_{1/2},F'{=}2\rangle$ transition, we find 3329.3(1.4) MHz for the tensor-shifted tune out of the $|2S_{1/2},F{=}2,m_F{=}0\rangle$ state with $\sigma^\pm$ light polarization and 3310.1(4.9) MHz for the tune out of the the scalar polarizability. This technique may be generalized for directly sensing spatially varying phase profiles.