Stable topological insulators achieved using high energy electron beams

Authors

Lukas Zhao, CUNY City CollegeFollow
Marcin Konczykowski, Universite Paris-Saclay
Haiming Deng, CUNY City CollegeFollow
Inna Korzhovska, CUNY City CollegeFollow
Milan Begliarbekov, CUNY City College
Zhiyi Chen, CUNY City CollegeFollow
Evangelos Papalazarou, Universite Paris-Saclay
Marino Marsi, Universite Paris-Saclay
Luca Perfetti, Universite Paris-Saclay
Andrzej Hruban, Institute of Electronic Materials Technology
Agnieszka Wolos, University of Warsaw
Lia Krusin-Elbaum, CUNY City CollegeFollow

Document Type

Article

Publication Date

3-10-2016

Abstract

Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (B2.5MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size.

Comments

This article was originally published in Nature Communications, available at DOI: 10.1038/ncomms10957.

This work is licensed under a Creative Commons Attribution 4.0 International License.