Stimulated Emission of Dark Matter Axion from Condensed Matter   Excitations
  We discuss a possible principle for detecting dark matter axions in galactic halos. If axions constitute a condensate in the Milky Way, stimulated emissions of the axions from a type of excitation in condensed matter can be detectable. We provide general mechanism for the dark matter emission, and, as a concrete example, an emission of dark matter axions from magnetic vortex strings in a type II superconductor are investigated along with possible experimental signatures. 
Naoto Yokoi and Eiji Saitoh
hep-ph astro-ph.CO cond-mat.mes-hall hep-th