Probing the axion-photon coupling with space-based gravitational waves detectors

TL;DR

This paper proposes a modification to space-based gravitational wave detectors to measure vacuum birefringence caused by axion dark matter, enhancing their sensitivity to low-mass axions with minimal impact on GW detection.

Contribution

It introduces a simple optical modification enabling gravitational wave detectors to probe axion-photon coupling via vacuum birefringence measurements.

Findings

Enhanced sensitivity to low-mass axions in future detectors

Minimal impact on gravitational wave detection sensitivity

Potential to make space-based detectors the most sensitive experiments for axion searches

Abstract

We propose a simple modification of space-based gravitational wave (GW) detector optical benches which would enable the measurement of vacuum birefringence of light induced by axion dark matterthrough its coupling to electromagnetism. Specifically, we propose to change a half-wave plate by a circular polarizer. While marginally affecting the sensitivity to GW by a factor $\sqrt{2}$, we show that such an adjustment would make future detectors such as LISA, TianQin, Taiji and Big-Bang Observer the most sensitive experiments at low axion masses