  Nitrogen vacancy doped SmN$_{1-\delta}$ is a semiconductor which lies in the
intermediary between insulating-ferromagnetic SmN and
metallic-anti-ferromagnetic Sm. The dopant electrons resulting from nitrogen
vacancies have recently been predicted to lie in a band precipitated by a
majority-spin 4$f$ level on the six Sm ions neighbouring each nitrogen vacancy,
an in-gap state $\sim$1 eV below the 4$f$ states in stoichiometric SmN. Optical
data reported here corroborate the prediction along with an extended
computational study. Electrical transport measurements show the transition from
an insulating to metallic state with a hopping type conductivity in dilutely
doped films. We provide strong evidence that electron transport is mediated by
a dispersion-less majority spin defect band implying triplet type
superconductivity, the location of which in the SmN-Sm phase diagram suggests
the location of a quantum critical point.
