Proximity effects between topological insulators and insulating ferromagnets

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Abstract/Contents

Abstract
To investigate the effects due to proximity between a three-dimensional topological insulator (TI) and an insulating ferromagnet (IF), TI-IF thin film bilayers were fabricated with pulsed laser deposition. Either bismuth(III) selenide (Bi2Se3) or bismuth-antimony(III) telluride (BST) was used for the TI layer, whereas the IF layer was formed by the Heisenberg ferromagnet EuS. While a positive magnetoresistance was observed above the Curie temperature of EuS, as ubiquitously observed in high-quality TI thin films, an unusual negative magnetoresistance was observed below the Curie temperature in the variable-range hopping regime. The angular dependence of such negative magnetoresistance indicates an orbit origin. Specific to BST-EuS bilayers, when the bulk conduction is minimized, magnetic anomalies in AC susceptibility were observed concurrently with resistive anomalies at the same temperatures, suggesting an interface magnetic order. These phenomena together suggest two-stage proximity effects between the topological insulators and the insulating ferromagnet, and provide first steps to realize the half-integer quantum anomalous Hall effect.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2018; ©2018
Publication date 2018; 2018
Issuance monographic
Language English

Creators/Contributors

Author Yang, Qi
Degree supervisor Kapitulnik, Aharon
Thesis advisor Kapitulnik, Aharon
Thesis advisor Fisher, Ian R. (Ian Randal)
Thesis advisor Qi, Xiaoliang
Degree committee member Fisher, Ian R. (Ian Randal)
Degree committee member Qi, Xiaoliang
Associated with Stanford University, Department of Physics.

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Qi Yang.
Note Submitted to the Department of Physics.
Thesis Thesis Ph.D. Stanford University 2018.
Location electronic resource

Access conditions

Copyright
© 2018 by Qi Yang

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