Harvesting quantum coherence from axion dark matter.

Quantum coherence is one of the most striking features of quantum mechanics rooted in the superposition principle. Recently it has been demonstrated that it is possible to harvest the quantum coherence from a coherent scalar field. In order to explore a new method of detecting axion dark matter, we quantify a coherent measure of a detector and show that the detector can harvest the quantum coherence from the axion dark matter.