Scanning tunneling microscopy and spectroscopy of topological materials and heterostructures in thin films and devices

This dissertation reports the results of scanning tunneling microscopy experiments probing the physics of thin films of topological materials. A 3D topological insulator Bi2Te3 and a 2D topological insulator WTe2, grown epitaxially, are studied with atomic resolution, and their physics is probed using in-situ back gating. The development of the back-gating process in a scanning tunneling microscope is one of the main results of this work and is reported in detail. The band structure of the monolayer WTe2 is observed to be drastically changing upon the application of electric field through the back gate. The complex effect of the gate-induced electric field on monolayer WTe2 is explored and discussed. A study of the spatial extent of 1D edge states of WTe2 is presented. A new process combining nanopatterned superconductors and topological materials is proposed and implemented. The proposed geometry in devices suitable for scanning tunneling microscopy studies opens up many new possibilities to explore the proximity effect in topological materials for future Majorana platform realization.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2020

Author dc:creator

• Maximenko, Yulia

Contributors dc:contributor

• Madhavan, Vidya
• Eckstein, James
• Hughes, Taylor
• Kwiat, Paul
• Stack, John

• scanning tunneling microscopy, topological insulators, back gating, monolayer, molecular beam epitaxy

Statement dc:rights

• Copyright 2020 Yulia Maximenko

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/108241

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/108241