Determine vortex relaxation and release dynamics around laboratory magnets

Determine the timescale on which photon vortices reach equilibrium around a laboratory magnet and whether those vortices are released when the magnet is switched off, thereby establishing the residual background vector potential relevant to axial-photon dark-matter searches.

Background

In the massive-photon realization of the axial-photon coupling, photon vortices can discharge large background vector potentials. This may substantially alter laboratory signals, but the equilibrium and nonequilibrium dynamics of vortices near magnets are not calculated. In particular, the accumulation time and the response after removal of the magnetic source determine whether the vector-potential-based signal is present during an experiment.

References

Further study is required to understand the timescale to reach such a state, and whether the vortices are released when the magnet is switched off.

— Ultralight Axial Dark Matter  (2609.10671 - Hook et al., 9 Sep 2026) in Section 3.2, paragraph “Background Potentials”

The vector potential of a laboratory magnet may also be suppressed by accumulating Earth-bound vortices near it, though it is not clear if this would happen on a realistic timescale, since the size of a magnet is much smaller than $d_\oplus$.

— Ultralight Axial Dark Matter  (2609.10671 - Hook et al., 9 Sep 2026) in Appendix A.3, paragraph “Heavy Higgs Benchmark”