Generating axion dark matter through the kinetic misalignment mechanism
implies the generation of large asymmetries for Standard Model fermions in the
early universe. Even if these asymmetries are washed out at later times, they
can trigger a chiral plasma instability in the early universe. Similarly, a
direct coupling of the axion with the hypercharge gauge field can trigger a
tachyonic instability. These instabilities produce helical magnetic fields,
which are preserved until the electroweak phase transition. At the electroweak
phase transition, these become a source of baryon asymmetry, which can be much
more efficient than the original axiogenesis proposal. We discuss constraints
on axion dark matter production from the overproduction of the baryon asymmetry
as well as a minimal, albeit fine-tuned setup, where both the correct dark
matter abundance and baryon asymmetry can be achieved. For a given axion decay
constant, this leads to a sharp prediction for the mass of the radial direction
of the Peccei Quinn field, which is a soft mass scale in supersymmetric
theories.Comment: 29 pages + references, 5 figure