Possible resonance effect of axionic dark matter in Josephson junctions
Abstract
We provide theoretical arguments that dark matter axions from the galactic halo that pass through the earth may generate a small observable signal in resonant S/N/S Josephson junctions. The corresponding interaction process is based on uniqueness of the gauge-invariant axion Josephson phase angle modulo 2 pi and is predicted to produce a small Shapiro step-like feature without externally applied microwave radiation when the Josephson frequency resonates with the axion mass. A resonance signal of so far unknown origin observed in [C. Hoffmann et al. PRB 70, 180503(R) (2004)] is consistent with our theory and can be interpreted in terms of an axion mass of 0.11 meV and a local galactic axionic dark matter density of 0.05 GeV/cm^3. We discuss future experimental checks to confirm the dark-matter nature of the observed signal.
Cite
@article{arxiv.1309.3790,
title = {Possible resonance effect of axionic dark matter in Josephson junctions},
author = {Christian Beck},
journal= {arXiv preprint arXiv:1309.3790},
year = {2013}
}
Comments
replaced by final version to appear in Phys. Rev. Lett