Charge transfer in cold collisions of Be$^+$ + Be

We study charge transfer in collisions of cold Be$^+$ and Be in an external magnetic field. The atom-ion interaction is modeled by high-level \emph{ab-initio} potential energy curves, including the dipole-dipole terms, as well as Zeeman and hyperfine couplings. The scattering calculations are performed for a range of experimentally accessible magnetic fields and different initial hyperfine states using fully-quantum coupled channel formalism. We report detailed inelastic and charge-exchange cross sections for different isotopes of Be. In addition, we predict a number of magnetic Feshbach resonances and discuss their applications on controlled charge transfer in cold quantum gases and optically trapped systems.