Fully opposite spin polarization of electron and hole bands in DyN and related band structures of GdN and HoN

Abstract

© 2015 American Physical Society. Using quasiparticle self-consistent GW calculations, we show that DyN has an unusual nearly zero indirect gap semimetallic band structure in which the states near the valence band maximum are fully minority spin polarized at Γ while the states near the conduction band minimum (at X) have fully majority spin character. This arises due to a strong hybridization of one of the minority spin f states of dysprosium with the N-2p bands. The reason why only one of the f bands hybridizes is explained using symmetry arguments. We show that in HoN, this hybridization is already strongly reduced because of the deeper Ho-4f minority spin states.