Prospects for Precise Measurements with Echo Atom Interferometry

TL;DR

This paper reviews the development and application of echo atom interferometers for precise measurements of gravitational acceleration and atomic recoil frequency, highlighting experimental results and systematic effect mitigation.

Contribution

It introduces optimized echo interferometer configurations for high-precision measurements of $g$ and $ u_q$, demonstrating significant experimental advancements.

Findings

Measured atomic recoil frequency with 37 ppb uncertainty

Achieved gravitational acceleration measurement with 75 ppb precision

Outlined techniques to reduce systematic errors using off-resonant excitation

Abstract

Echo atom interferometers have emerged as interesting alternatives to Raman interferometers for the realization of precise measurements of the gravitational acceleration $g$ and the determination of the atomic fine structure through measurements of the atomic recoil frequency $\omega_q$. Here we review the development of different configurations of echo interferometers that are best suited to achieve these goals. We describe experiments that utilize near-resonant excitation of laser-cooled rubidium atoms by a sequence of standing wave pulses to measure $\omega_q$ with a statistical uncertainty of 37 parts per billion (ppb) on a time scale of $\sim 50$ ms and $g$ with a statistical precision of 75 ppb. Related coherent transient techniques that have achieved the most statistically precise measurements of atomic g-factor ratios are also outlined. We discuss the reduction of prominent systematic effects in these experiments using off-resonant excitation by low-cost, high-power lasers.