Abstract
We provide theoretical arguments that dark-matter axions from the galactic halo that pass through Earth may generate a small observable signal in resonant S/N/S Josephson junctions. The corresponding interaction process is based on the uniqueness of the gauge-invariant axion Josephson phase angle modulo and is predicted to produce a small Shapiro steplike feature without externally applied microwave radiation when the Josephson frequency resonates with the axion mass. A resonance signal of so far unknown origin observed by C. Hoffmann et al. [Phys. Rev. B 70, 180503(R) (2004)] is consistent with our theory and can be interpreted in terms of an axion mass and a local galactic axionic dark-matter density of . We discuss future experimental checks to confirm the dark-matter nature of the observed signal.
- Received 17 September 2013
DOI:https://doi.org/10.1103/PhysRevLett.111.231801
© 2013 American Physical Society
Synopsis
Catching Dark Matter Red Handed
Published 2 December 2013
The elusive dark matter candidates called axions might set off alarm bells in a superconducting detector.
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