The interface between magnetic materials and topological insulators can drive the formation of exotic phases of matter and enable functionality through manipulation of the strong spin polarized transport. Here, we report that the spin-momentum-locked transport in the topological insulator Bi2Se3 is completely suppressed by scattering at a heterointerface with the kagome-lattice paramagnet, Co7Se8. Bi2Se3−Co7Se8−Bi2Se3 trilayer heterostructures were grown using molecular beam epitaxy. Magnetotransport measurements revealed a substantial suppression of the weak antilocalization effect for Co7Se8 at thicknesses as thin as a monolayer, indicating a strong dephasing mechanism. Bi2−xCoxSe3 films, where Co is in a non-magnetic 3+ state, show weak antilocalization that survives to x=0.5, which, in comparison with the heterostructures, suggests the unordered moments of the Co2+ act as a far stronger dephasing element. This work highlights several important points regarding spin-polarized transport in topological insulator interfaces and how magnetic materials can be integrated with topological materials to realize both exotic phases as well as novel device functionality.
@article{arxiv.2009.06827,
title = {Strong spin-dephasing in a topological insulator - paramagnet heterostructure},
author = {Jason Lapano and Alessandro R. Mazza and Haoxiang Li and Debangshu Mukherjee and Elizabeth M. Skoropata and Jong Mok Ok and Hu Miao and Robert G. Moore and Thomas Z. Ward and Gyula Eres and Ho Nyung Lee and Matthew Brahlek},
journal= {arXiv preprint arXiv:2009.06827},
year = {2020}
}