  The angular momentum of evanescent light fields has been studied in
nano-optics and plasmonics, but not in the microwave regime. Here we predict
non-contact pumping of electron spin currents in conductors by the evanescent
stray fields of excited magnetic nanostructures. The coherent transfer of the
photon to the electron spin is proportional to the $g$-factor, which is large
in narrow-gap semiconductors and surface states of topological insulators. The
spin pumping current is chiral when the spin susceptibility displays
singularities that indicate collective states. However, 1D systems with linear
dispersion at the Fermi energy such as metallic carbon nanotubes are an
exception since spin pumping is chiral even without interactions.
