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

摘要

We report that thin films of a prototype topological insulator,Bi$_{2}$Se$_{3}$, can be epitaxially grown onto the (0001) surface ofBaFe$_{12}$O$_{19}$(BaM), a magnetic insulator with high Curie temperature andlarge perpendicular anisotropy. In the Bi$_2$Se$_3$ thin films grown onnon-magnetic substrates, classic weak antilocalization (WAL) is manifested ascusp-shaped positive magnetoresistance (MR) in perpendicular magnetic fieldsand parabola-shaped positive MR in parallel fields, whereas inBi$_{2}$Se$_{3}$/BaM heterostructures the low field MR is parabola-shaped,which is positive in perpendicular fields and negative in parallel fields. Themagnetic field and temperature dependence of the MR is explained as aconsequence of the suppression of WAL due to strong magnetic interactions atthe Bi$_{2}$Se$_{3}$/BaM interface.