Axion Dark Matter Search with Interferometric Gravitational Wave Detectors

Axion dark matter differentiates the phase velocities of the circular-polarized photons. In this Letter, a scheme to measure the phase difference by using a linear optical cavity is proposed. If the scheme is applied to the Fabry-Pérot arm of Advanced-LIGO-like (Cosmic-Explorer-Like) gravitational wave detector, the potential sensitivity to the axion-photon coupling constant, gaγ, reaches gaγ≃8×10⁻¹³ GeV⁻¹(4×10⁻¹⁴ GeV⁻¹) at the axion mass m≃3×10⁻¹³ eV (2×10⁻¹⁵ eV) and remains at around this sensitivity for three orders of magnitude in mass. Furthermore, its sensitivity has a sharp peak reaching gaγ≃10⁻¹⁴ GeV⁻¹(8×10⁻¹⁷ GeV⁻¹) at m=1.563×10⁻¹⁰ eV (1.563×10⁻¹¹ eV). This sensitivity can be achieved without losing any sensitivity to gravitational waves.