"Phase Separation of Dirac Electrons in Topological Insulators at the Spatial Limit"

Carolina Parra: Thiago Henrique Rodrigues da Cunha, Alex W. Contryman, Desheng Kong, Francisco Montero-Silva† Pedro Henrique Rezende Gonçalves, Diogo Duarte Dos Reis, Paula Giraldo-Gallo, Rodrigo Segura , Fernanda Olivares, Francis Niestemski, Yi Cui, Rogerio Magalhaes-Paniago, and Hari C. Manoharan; American Chemical Society, 12/27/16.

Additional Authors: Thiago Henrique Rodrigues da Cunha, Alex W. Contryman, Desheng Kong, Francisco Montero-Silva† Pedro Henrique Rezende Gonçalves, Diogo Duarte Dos Reis, Paula Giraldo-Gallo, Rodrigo Segura , Fernanda Olivares, Francis Niestemski, Yi Cui, Rogerio Magalhaes-Paniago, and Hari C. Manoharan

Abstract:

In this work we present unique signatures manifested by the local electronic properties of the topological surface state in Bi2Te3 nanostructures as the spatial limit is approached. We concentrate on the pure nanoscale limit (nanoplatelets) with spatial electronic resolution down to 1 nm. The highlights include strong dependencies on nanoplatelet size: (1) observation of a phase separation of Dirac electrons whose length scale decreases as the spatial limit is approached, and (2) the evolution from heavily n-type to lightly n-type surface doping as nanoplatelet thickness increases. Our results show a new approach to tune the Dirac point together with reduction of electronic disorder in topological insulator (TI) nanostructured systems. We expect our work will provide a new route for application of these nanostructured Dirac systems in electronic devices.

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