A Resonant Mode for Gravitational Wave Detectors based on Atom Interferometry

TL;DR

This paper proposes a resonant atom interferometric gravitational wave detector that enhances sensitivity at specific frequencies, enabling targeted astrophysical and cosmological gravitational wave searches with flexible operation modes.

Contribution

Introduction of a resonant mode for atom interferometric gravitational wave detectors that allows narrow-band sensitivity and rapid switching between detection modes.

Findings

Resonant mode increases detector sensitivity at target frequencies.

Detector can switch between broadband and narrow-band modes rapidly.

Potential to detect inflationary gravitational waves down to ^{-14}.

Abstract

We describe an atom interferometric gravitational wave detector design that can operate in a resonant mode for increased sensitivity. By oscillating the positions of the atomic wavepackets, this resonant detection mode allows for coherently enhanced, narrow-band sensitivity at target frequencies. The proposed detector is flexible and can be rapidly switched between broadband and narrow-band detection modes. For instance, a binary discovered in broadband mode can subsequently be studied further as the inspiral evolves by using a tailored narrow-band detector response. In addition to functioning like a lock-in amplifier for astrophysical events, the enhanced sensitivity of the resonant approach also opens up the possibility of searching for important cosmological signals, including the stochastic gravitational wave background produced by inflation. We give an example of detector parameters which would allow detection of inflationary gravitational waves down to $\Omega_\text{GW} \sim 10^{-14}$ for a two satellite space-based detector.