Inertial Torsion Noise in Matter-Wave Interferometers for Gravity Experiments

TL;DR

This paper analyzes inertial torsion noise in matter-wave interferometers, providing analytical models, validating them with simulations, and estimating effects for future experiments testing quantum gravity with tiny particles.

Contribution

It introduces a theoretical framework for inertial torsion noise in matter-wave interferometry and validates it through simulations, aiding future high-precision gravity experiments.

Findings

Ambient gas causes mild ITN restrictions.

Analytical expressions match Monte Carlo simulations.

Estimated effects for next-gen experiments with femtogram particles.

Abstract

Matter-wave interferometry is susceptible to non-inertial noise sources, which can induce dephasing and a resulting loss of interferometric visibility. Here, we focus on inertial torsion noise (ITN), which arises from the rotational motion of the experimental apparatus suspended by a thin wire and subject to random external torques. We provide analytical expressions for the ITN noise starting from generalized Langevin equations describing the experimental box which can then be used together with the transfer function to obtain the dephasing factor. We verify the theoretical modelling and the validity of the approximations using Monte Carlo simulations, obtaining good agreement between theory and numerics. As an application, we estimate the size of the effects for the next generation of interferometry experiments with femtogram particles, which could be used as the building block for entanglement-based tests of the quantum nature of gravity. We find that the ambient gas is a weak source of ITN, posing mild restrictions on the ambient pressure and temperature. We discuss the general ITN constraints by assuming a Langevin equation parameterized by three phenomenological parameters.