The effect of electron-magnon interaction on the band structure of ferromagnetic semiconductors with application to EuO and EuS

The exact nature of the conduction band states in the ferromagnetic semiconductors EuO and EuS at T=0 is investigated. No corrections to standard band theory occur for majority spin states, but shifts and broadening occur in minority spin states due to electron-magnon interaction. Previous work incorporating this effect assumes a non-degenerate s band instead of the more realistic d band used here, but qualitative comparison is possible.