Gravitational Wave Detection with Atom Interferometry

TL;DR

This paper proposes two atom interferometer-based gravitational wave detectors, one on Earth and one in space, capable of detecting signals in frequency ranges inaccessible to existing detectors like LIGO and LISA.

Contribution

It introduces novel terrestrial and satellite atom interferometer designs that enhance gravitational wave detection sensitivity and background suppression using laser comparisons and ballistic atoms.

Findings

Terrestrial detector sensitivity ~10^{-19}/√Hz in 1-10 Hz band

Satellite detector sensitivity ~10^{-20}/√Hz, comparable to LISA

Enhanced signal detection through laser-based comparison of separated atom interferometers

Abstract

We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford $10 \text{m}$ atom interferometer presently under construction. The terrestrial experiment can operate with strain sensitivity $ \sim \frac{10^{-19}}{\sqrt{\text{Hz}}}$ in the 1 Hz - 10 Hz band, inaccessible to LIGO, and can detect gravitational waves from solar mass binaries out to megaparsec distances. The satellite experiment probes the same frequency spectrum as LISA with better strain sensitivity $ \sim \frac{10^{-20}}{\sqrt{\text{Hz}}}$. Each configuration compares two widely separated atom interferometers run using common lasers. The effect of the gravitational waves on the propagating laser field produces the main effect in this configuration and enables a large enhancement in the gravitational wave signal while significantly suppressing many backgrounds. The use of ballistic atoms (instead of mirrors) as inertial test masses improves systematics coming from vibrations and acceleration noise, and reduces spacecraft control requirements.