paper

Proximity effect between a topological insulator and a magnetic insulator with large perpendicular anisotropy

arXiv:1504.01922 · doi:10.1063/1.4895073

Abstract

We report that thin films of a prototype topological insulator, Bi $_{2}$ Se $_{3}$ , can be epitaxially grown onto the (0001) surface of BaFe $_{12}$ O $_{19}$ (BaM), a magnetic insulator with high Curie temperature and large perpendicular anisotropy. In the Bi $_{2}$ Se $_{3}$ thin films grown on non-magnetic substrates, classic weak antilocalization (WAL) is manifested as cusp-shaped positive magnetoresistance (MR) in perpendicular magnetic fields and parabola-shaped positive MR in parallel fields, whereas in Bi $_{2}$ Se $_{3}$ /BaM heterostructures the low field MR is parabola-shaped, which is positive in perpendicular fields and negative in parallel fields. The magnetic field and temperature dependence of the MR is explained as a consequence of the suppression of WAL due to strong magnetic interactions at the Bi $_{2}$ Se $_{3}$ /BaM interface.

5 pages, 5 figures, supplemental material available upon request or visit the APL website