Axion Dark Matter Search with Interferometric Gravitational Wave Detectors

Abstract

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-P\'erot arm of Advanced-LIGO-like (Cosmic-Explorer-Like) gravitational wave detector, the potential sensitivity to the axion-photon coupling constant, ${g}_{\mathrm{a}\ensuremath{\gamma}}$, reaches ${g}_{\mathrm{a}\ensuremath{\gamma}}\ensuremath{\simeq}8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}(4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}14}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1})$ at the axion mass $m\ensuremath{\simeq}3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\text{ }\text{ }\mathrm{eV}$ ($2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}\text{ }\text{ }\mathrm{eV}$) and remains at around this sensitivity for three orders of magnitude in mass. Furthermore, its sensitivity has a sharp peak reaching ${g}_{\mathrm{a}\ensuremath{\gamma}}\ensuremath{\simeq}{10}^{\ensuremath{-}14}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}(8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}17}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1})$ at $m=1.563\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}\text{ }\text{ }\mathrm{eV}$ ($1.563\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\text{ }\text{ }\mathrm{eV}$). This sensitivity can be achieved without losing any sensitivity to gravitational waves.