High spin polarization at the interface between a Fe monolayer and InAs(110)

The magnetic and electronic properties of a Fe monolayer on InAs(110) are calculated with an ab initio method using the density-functional theory. We find that the relaxation of the InAs(110) surface is completely lifted and that the Fe atom is located in the center of the triangle formed of two As atoms and an adjacent In atom. The Fe bonding is largely determined by a molecularlike interaction of As and In orbitals with the Fe d levels. In particular, the density of states at the Fermi level is dominated by a bond between minority Fe $d_{\mathrm{xy}},$ $d_{\mathrm{zy}}$ levels and As $p_x,$ In $\mathrm{sp}$ levels. This leads to a large value of 80% spin polarization on the Fe side and 60% on the InAs side of the interface albeit of different orientation. Into the crystal the spin-polarization exhibits a damped oscillation.