Atom Interferometer Tests of Dark Matter

TL;DR

This paper explores using atom interferometers to detect light dark matter particles below 1 GeV, highlighting their sensitivity to low momentum transfers and potential to fill gaps in current detection capabilities.

Contribution

It introduces a framework for analyzing dark matter interactions in atom interferometers, considering multiple detection channels and demonstrating their competitive sensitivity for sub-GeV dark matter.

Findings

Atom interferometers can probe dark matter with masses below 10 keV.

Future experiments could reach cross-section sensitivities around 10^{-42} cm^2.

They can uniquely detect a dark matter sub-component with very low mass.

Abstract

Direct detection experiments for dark matter are increasingly ruling out large parameter spaces. However, light dark matter models with particle masses $<$ GeV are still largely unconstrained. Here we examine a proposal to use atom interferometers to detect a light dark matter subcomponent at sub-GeV masses. We describe the decoherence and phase shifts caused by dark matter scattering off of one "arm" of an atom interferometer using a generalized dark matter direct detection framework. This allows us to consider multiple channels: nuclear recoils, hidden photon processes, and axion interactions. We apply this framework to several proposed atom interferometer experiments. Because atom interferometers are sensitive to extremely low momentum deposition and their coherent atoms may give them a boost in sensitivity, these experiments will be highly competitive and complementary to other direct detection methods. In particular, atom interferometers are uniquely able to probe a dark matter sub-component with $m_\chi \lesssim 10~\rm{keV}$. We find that, for a mediator mass $m_\phi=10^{-5}m_\chi$, future atom interferometers could close a gap in the existing constraints on nuclear recoils down to $\bar{\sigma}_n \sim 10^{-42}~\rm{cm}^2$ for $m_\chi \sim 10^{-5} - 10^{-1}~\rm{MeV}$ dark matter masses.