Inducing magnetism onto the surface of a topological crystalline insulator

Inducing magnetism onto a topological crystalline insulator (TCI) has been predicted to result in several novel quantum electromagnetic effects. This is a consequence of the highly strain-sensitive band topology of such symmetry-protected systems. We thus show that placing the TCI surface of SnTe in...

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Bibliographic Details
Main Authors: Assaf, Badih A., Satpati, B., Heiman, D., Katmis, Ferhat, Wei, Peng, Chang, Cui-zu, Moodera, Jagadeesh
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: American Physical Society 2015
Online Access:http://hdl.handle.net/1721.1/96960
https://orcid.org/0000-0002-2480-1211
https://orcid.org/0000-0001-7413-5715
https://orcid.org/0000-0003-2289-6007
Description
Summary:Inducing magnetism onto a topological crystalline insulator (TCI) has been predicted to result in several novel quantum electromagnetic effects. This is a consequence of the highly strain-sensitive band topology of such symmetry-protected systems. We thus show that placing the TCI surface of SnTe in proximity to EuS—a ferromagnetic insulator—induces magnetism at the interface between SnTe and EuS, and thus breaks time-reversal symmetry in the TCI. Magnetotransport experiments on SnTe-EuS-SnTe trilayer devices reveal a hysteretic lowering of the resistance at the TCI surface that coincides with an increase in the density of magnetic domain walls. This additional conduction could be a signature of topologically protected states within domain walls. Additionally, a hysteretic anomalous Hall effect reveals that the usual in-plane magnetic moment of the EuS layer is canted towards a perpendicular direction at the interface. These results are evidence of induced magnetism at the SnTe-EuS interfaces, resulting in broken time-reversal symmetry in the TCI.