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 with a machine-learned Hubbard U correction [Yu, npj Comput. Mater. 6, 180 (2020)2057-396010.1038/s41524-020-00446-9] 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 states. For all interface configurations studied here, the induced magnetic moment in the InAs is small. Our results suggest that this interface, in its coherent form studied here, may not be promising for inducing equilibrium magnetic properties in InAs.
Bibliographical noteFunding Information:
We thank P. Krogstrup and Y. Liu from the University of Copenhagen and Microsoft Quantum Materials Lab Copenhagen and S. Martí-Sanchez from the Catalan Institute of Nanoscience and Nanotechnology for helpful discussions on the details of their HAADF-STEM experiments and DFT calculations. We thank S. Frolov from the University of Pittsburgh, P. Crowell from the University of Minnesota, and C. Palmstrøm from the University of California, Santa Barbara, for helpful discussions. This research was funded by the Department of Energy (DOE) through Grant No. DE-SC0019274. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02-05CH11231.
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