A theoretical study asks whether treating axion dark matter as a classical field is reliable. Using a fully quantum detector model, it finds the field could be in a non-classical state, but mode averaging, small noise and weak axion coupling wash out any quantum signatures.

— via arXiv — Astro-ph, Yunjia Bao, Dhong Yeon Cheong, Nicholas L. Rodd, Joey Takach, Lian-Tao Wang, Kevin Zhou