Three-path atom interferometry with large momentum separation

TL;DR

This paper demonstrates a large-momentum-separation three-path atom interferometer with high phase stability, achieved through careful atom optics design, enabling potential precision measurements of fundamental constants.

Contribution

The authors scale up a symmetric three-path atom interferometer to large momentum separation while maintaining phase stability, advancing the capabilities of free-space atom interferometry.

Findings

Achieved phase stability at 112 photon recoil momenta

Phase evolution is quadratic with number of recoils

Interferometer phase rate reaches 7×10^7 radians/sec

Abstract

We demonstrate the scale up of a symmetric three-path contrast interferometer to large momentum separation. The observed phase stability at separation of 112 photon recoil momenta ($112\hbar k$) exceeds the performance of earlier free-space interferometers. In addition to the symmetric interferometer geometry and Bose-Einstein condensate source, the robust scalability of our approach relies crucially on the suppression of undesired diffraction phases through a careful choice of atom optics parameters. The interferometer phase evolution is quadratic with number of recoils, reaching a rate as high as $7\times10^7$ radians/s. We discuss the applicability of our method towards a new measurement of the fine-structure constant and a test of QED.