Enhancing photon-axion conversion probability with squeezed coherent states
Phys. Rev. D 113, 023539 – Published 23 January, 2026
DOI: https://doi.org/10.1103/c741-bwvs
Abstract
In particle physics, axions and axionlike particles are ubiquitous. Remarkably, ultralight axions could constitute dark matter or dark energy. Therefore, it is important to detect axions experimentally. In the presence of a magnetic field, a photon can be converted into an axion, and vice versa. Utilizing the conversion phenomenon, several methods for detecting axions have been proposed. To improve detectability, it is desirable to use quantum sensing. However, since the conversion process is usually treated as classical wave dynamics, it is unclear how to incorporate quantum effects such as entanglement. In this work, we formulate the photon-axion conversion in a quantum field theoretical manner. As a result, we succeed in evaluating the conversion probability from a photon quantum state to an axion quantum state. In particular, it turns out that squeezed coherent states can enhance the conversion probability.
