Enhanced surface state protection and band gap in the topological insulator PbBi4Te4S3

Topological insulators (TIs) with an inverted bulk band and a strong spin-orbit coupling exhibit gapless topological surface states (TSSs) protected by time-reversal symmetry. Helical spin textures driven by spin-momentum locking offer the opportunity to generate spin-polarized currents and therefor...

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Detalles Bibliográficos
Autores: Sumida, Kazuki, Natsumeda, T., Miyamoto, Koji, Silkin, Igor V., Kuroda, K., Shirai, K., Zhu, Siyuan, Taguchi, K., Arita, M., Fujii, Jun, Varykhalov, A. Yu., Rader, Oliver, Golyashov, V. A., Kokh, Konstantin A., Tereshchenko, Oleg E., Chulkov, Eugene V., Okuda, Taichi, Kimura, A.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/244587
Acceso en línea:http://hdl.handle.net/10261/244587
Access Level:acceso abierto
Descripción
Sumario:Topological insulators (TIs) with an inverted bulk band and a strong spin-orbit coupling exhibit gapless topological surface states (TSSs) protected by time-reversal symmetry. Helical spin textures driven by spin-momentum locking offer the opportunity to generate spin-polarized currents and therefore TIs are expected to be used for future spintronic applications. For practical applications TIs are urgently required that are operable at room temperature due to a wide bulk band gap as well as a distinct topological surface state that is robust to atmospheric exposure. Here we show two distinguishable TSSs originating from different terminations on PbBi4Te4S3 by using spin- and angle-resolved photoemission spectroscopy. We find that one TSS is persistently observed, while the other becomes invisible upon intentional oxygen exposure. The result signifies the presence of a protected TSS buried under the topmost surface. Our finding paves the way for realizing a topological spintronics device under atmospheric conditions.

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