Understanding the giant enhancement of exchange interaction in Bi.sub.2./sub.Se.sub.3./sub.-EuS heterostructures

0484704 - FZÚ 2018 RIV US eng J - Journal Article
Kim, J. - Kim, K.W. - Wang, H. - Sinova, Jairo - Wu, R.
Understanding the giant enhancement of exchange interaction in Bi₂Se₃-EuS heterostructures.
Physical Review Letters. Roč. 119, č. 2 (2017), s. 1-5, č. článku 027201. ISSN 0031-9007. E-ISSN 1079-7114
EU Projects: European Commission(XE) 610115 - SC2
Institutional support: RVO:68378271
Keywords : doped topological insulator * augmented-wave method * spin-orbit torque * ferrimagnetic insulator * noncollinear magnetism * electric-field * temperature * surface * state
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 8.839, year: 2017

A recent experiment indicated that a ferromagnetic EuS film in contact with a topological insulator Bi2Se3 might show a largely enhanced Curie temperature and perpendicular magnetic anisotropy [F. Katmis et al., Nature (London) 533, 513 (2016).]. Through systematic density functional calculations, we demonstrate that in addition to the factor that Bi2Se3 has a strong spin orbit coupling, the topological surface states are crucial to make these unusual behaviors robust as they hybridize with EuS states and extend rather far into the magnetic layers. The magnetic moments of Eu atoms are nevertheless not much enhanced, unlike what was reported in the experiment. Our results and model analyses provide useful insights for how these quantities are linked, and pave a way for the control of properties of magnetic films via contact with topological insulators.

Permanent Link: http://hdl.handle.net/11104/0279838