Fluctuation-induced Neel and Bloch skyrmions at topological insulator surfaces

Nogueira, Flavio S.
Eremin, Ilya
Katmis, Ferhat
Moodera, Jagadeesh S.
van den Brink, Jeroen
Kravchuk, Volodymyr P.
Ferromagnets in contact with a topological insulator have become appealing candidates for spintronics due to the presence of Dirac surface states with spin-momentum locking. Because of this, bilayer Bi2Se3-EuS structures, for instance, show a finite magnetization at the interface at temperatures well exceeding the Curie temperature of bulk EuS. Here, we determine theoretically the effective magnetic interactions at a topological insulator-ferromagnet interface above themagnetic ordering temperature. We show that by integrating out the Dirac fermion fluctuations an effective Dzyaloshinskii-Moriya interaction and magnetic charging interaction emerge. As a result, individual magnetic skyrmions and extended skyrmion lattices can form at the interfaces of ferromagnets and topological insulators, the first indications of which have been very recently observed experimentally.

Citation Formats
F. S. Nogueira, I. Eremin, F. Katmis, J. S. Moodera, J. van den Brink, and V. P. Kravchuk, “Fluctuation-induced Neel and Bloch skyrmions at topological insulator surfaces,” PHYSICAL REVIEW B, vol. 98, no. 6, pp. 0–0, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/68363.