IAS Fundamental Physics Seminar Series - Quantum and Classical Effects of Axion Dark Matter

Abstract
The search for axion dark matter is rapidly expanding, with new experiments deploying quantum sensing techniques to reach unprecedented precision. However, many works disagree over whether one needs to account for the quantum nature of the axion itself. In this talk, the speaker will resolve these issues by analyzing a fully quantized model of axion detection. He will show that the axion can easily evolve into a quantum state with no classical analogue, but that the intrinsically quantum effects of these states are strongly suppressed in the detector, and in practice unobservable. Similarly, the speaker will show how the effects of an axion "background corrected propagator", said to be inherently quantum, can also be derived classically. Thus, counterintuitively, the classical field approximation works even when the axion field's state is far from classical.