Hybrid semiconductor-ferromagnetic insulator heterostructures are interesting due to their tunable electronic transport, self-sustained stray field and local proximitized magnetic exchange. In this work, we present lattice matched hybrid epitaxy of semiconductor - ferromagnetic insulator InAs/EuS heterostructures and analyze the atomic-scale structure as well as their electronic and magnetic characteristics. The Fermi level at the InAs/EuS interface is found to be close to the InAs conduction band and in the bandgap of EuS, thus preserving the semiconducting properties. Both neutron and X-ray reflectivity measurements show that the ferromagnetic component is mainly localized in the EuS thin film with a suppression of the Eu moment in the EuS layer nearest the InAs. Induced moments in the adjacent InAs layers were not detected although our ab initio calculations indicate a small exchange field in the InAs layer. This work presents a step towards realizing high quality semiconductor - ferromagnetic insulator hybrids, which is a critical requirement for development of various quantum and spintronic applications without external magnetic fields.
@article{arxiv.1908.07096,
title = {Coherent Epitaxial Semiconductor-Ferromagnetic Insulator InAs/EuS Interfaces: Band Alignment and Magnetic Structure},
author = {Yu Liu and Alessandra Luchini and Sara Martí-Sánchez and Christian Koch and Sergej Schuwalow and Sabbir A. Khan and Tomaš Stankevič and Sonia Francoua and Jose R. L. Mardegan and Jonas A. Krieger and Vladimir N. Strocov and Jochen Stahn and Carlos A. F. Vaz and Mahesh Ramakrishnan and Urs Staub and Kim Lefmann and Gabriel Aeppli and Jordi Arbiol and Peter Krogstrup},
journal= {arXiv preprint arXiv:1908.07096},
year = {2019}
}