Precision atomic gravimeter based on Bragg diffraction

TL;DR

This paper introduces a highly sensitive atomic gravimeter using Bragg diffraction of cold atoms, offering advantages over traditional methods by reducing environmental susceptibility and achieving precise gravitational measurements.

Contribution

It demonstrates a novel Bragg-based atomic gravimeter with high sensitivity and the ability to be adapted into a gravity gradiometer, improving measurement robustness.

Findings

Achieved sensitivity of Δg/g = 2.7×10⁻⁹ with 1000s integration

Successfully built a Mach-Zehnder interferometer using Bragg scattering

Device can be converted into a gravity gradiometer with simple modifications

Abstract

We present a precision gravimeter based on coherent Bragg diffraction of freely falling cold atoms. Traditionally, atomic gravimeters have used stimulated Raman transitions to separate clouds in momentum space by driving transitions between two internal atomic states. Bragg interferometers utilize only a single internal state, and can therefore be less susceptible to environmental perturbations. Here we show that atoms extracted from a magneto-optical trap using an accelerating optical lattice are a suitable source for a Bragg atom interferometer, allowing efficient beamsplitting and subsequent separation of momentum states for detection. Despite the inherently multi-state nature of atom diffraction, we are able to build a Mach-Zehnder interferometer using Bragg scattering which achieves a sensitivity to the gravitational acceleration of $\Delta g/g = 2.7\times10^{-9}$ with an integration time of 1000s. The device can also be converted to a gravity gradiometer by a simple modification of the light pulse sequence.