Investigating the environmental dependence of ultralight scalar dark matter with atom interferometers

TL;DR

This paper explores how ultralight scalar dark matter interacts with the environment and affects atom interferometer signals, providing new constraints on dark matter properties through terrestrial experiments.

Contribution

It introduces a model including local exponential fluctuations of dark matter and calculates their effects on atom interferometer phase shifts and WEP violation signals.

Findings

The local matter distribution influences dark matter field amplitude.

Atom interferometers can detect phase shifts caused by dark matter interactions.

Constraints on dark matter coupling parameters are derived from terrestrial WEP tests.

Abstract

We study the environmental dependence of ultralight scalar dark matter (DM) with linear interactions to the standard model particles. The solution to the DM field turns out to be a sum of the cosmic harmonic oscillation term and the local exponential fluctuation term. The amplitude of the first term depends on the local DM density and the mass of the DM field. The second term is induced by the local distribution of matter, such as the Earth. And it depends not only on the mass of the Earth, but also the density of the Earth. Then, we compute the phase shift induced by the DM field in atom interferometers (AIs), through solving the trajectories of atoms. Especially, the AI signal for the violation of weak equivalence principle (WEP) caused by the DM field is calculated. Depending on the values of the DM coupling parameters, contributions to the WEP violation from the first and second terms of the DM field can be either comparable or one larger than the other. Finally, we give some constraints to DM coupling parameters using results from the terrestrial atomic WEP tests.