Fluctuation-induced N\'eel and Bloch skyrmions at topological insulator surfaces
Abstract
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 BiSe-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 {\it above} the magnetic 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 interfaces of ferromagnets and topological insulators, the first indications of which have been very recently observed experimentally.
Keywords
Cite
@article{arxiv.1804.07684,
title = {Fluctuation-induced N\'eel and Bloch skyrmions at topological insulator surfaces},
author = {Flavio S. Nogueira and Ilya Eremin and Ferhat Katmis and Jagadeesh Moodera and Jeroen van den Brink and Volodymyr Kravchuk},
journal= {arXiv preprint arXiv:1804.07684},
year = {2018}
}
Comments
LaTex, 11 pages including supplemental information, 4 figures; v2: revised version accepted for publication in PRB RC; v3: Typos corrected, additional affiliation and grant acknowledgment included. Matches published version