Atom interferometer as a freely falling clock for time-dilation measurements

TL;DR

This paper proposes a novel scheme for light-pulse atom interferometers to measure relativistic time dilation effects as freely falling clocks, enabling new local tests of gravitational time dilation with potential implementation in existing experiments.

Contribution

It introduces a new measurement scheme for atom interferometers to directly measure relativistic time dilation effects without additional experimental requirements.

Findings

Supports the scheme with relativistic effect analysis

Analyzes systematic effects comprehensively

Provides theoretical tools for modeling such interferometers

Abstract

Light-pulse atom interferometers based on single-photon transitions are a promising tool for gravitational-wave detection in the mid-frequency band and the search for ultralight dark-matter fields. Here we present a novel measurement scheme that enables their use as freely falling clocks directly measuring relativistic time-dilation effects. The proposal is particularly timely because it can be implemented with no additional requirements in Fermilab's MAGIS-100 experiment or even in the 10-m prototypes that are expected to start operating very soon. This will allow the unprecedented measurement of gravitational time dilation in a local experiment with freely falling atoms, which is out of reach even for the best atomic-fountain clocks based on microwave transitions. The results are supported by a comprehensive treatment of relativistic effects in this kind of interferometers as well as a detailed analysis of the main systematic effects. Furthermore, the theoretical methods developed here constitute a valuable tool for modelling light-pulse atom interferometers based on single-photon transitions in general.