  Recently, the EuS/InAs interface has attracted attention for the possibility
of inducing magnetic exchange correlations in a strong spin-orbit
semiconductor, which could be useful for topological quantum devices. We use
density functional theory (DFT) with a machine-learned Hubbard $U$ correction
[npj Comput. Mater. 6, 180 (2020)] to elucidate the effect of the bonding
configuration at the interface on the electronic structure. For all interface
configurations considered here, we find that the EuS valence band maximum (VBM)
lies below the InAs VBM. In addition, dispersed states emerge at the top of the
InAs VBM at the interface, which do not exist in either material separately.
These states are contributed mainly by the InAs layer adjacent to the
interface. They are localized at the interface and may be attributed to charge
transfer from the EuS to the InAs. The interface configuration affects the
position of the EuS VBM with respect to the InAs VBM, as well as the dispersion
of the interface state. For all interface configurations studied here, the
induced magnetic moment in the InAs is small. This suggests that this
interface, in its coherent form studied here, is not promising for inducing
equilibrium magnetic properties in InAs.
