Disorder enabled band structure engineering of a topological insulator surface.
Three-dimensional topological insulators are bulk insulators with Z2topological electronic order that gives rise to conducting light-like surface states. These surface electrons are exceptionally resistant to localization by non-magnetic disorder, and have been adopted as the basis for a wide range of proposals to achieve new quasiparticle species and device functionality. Recent studies have yielded a surprise by showing that in spite of resisting localization, topological insulator surface electrons can be reshaped by defects into distinctive resonance states. Here we use numerical simulations and scanning tunnelling microscopy data to show that these resonance states have significance well beyond the localized regime usually associated with impurity bands. At native densities in the model Bi2X3(X=Bi, Te) compounds, defect resonance states are predicted to generate a new quantum basis for an emergent electron gas that supports diffusive electrical transport.
Department of Physics, New York University, New York, New York 10003, USA.
Yishuai
Y
Xu
Department of Physics, New York University, New York, New York 10003, USA.
Janet
J
Chiu
Department of Physics, New York University, New York, New York 10003, USA.|Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Lin
L
Miao
Department of Physics, New York University, New York, New York 10003, USA.
Haowei
H
He
Massachusetts Institute of Technology, Department of Physics, Cambridge, Massachusetts 02139, USA.|Department of Physics, Stanford University, Stanford, California 94305, USA.
Zhanybek
Z
Alpichshev
Department of Physics, Stanford University, Stanford, California 94305, USA.
A
A
Kapitulnik
Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA.
Rudro R
RR
Biswas
Department of Physics, New York University, New York, New York 10003, USA.|NYU-ECNU Institute of Physics at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China.
L Andrew
LA
Wray