A quantum spin Hall (QSH) insulator hosts topological states at the one-dimensional (1D) edge, along which backscattering by nonmagnetic impurities is strictly prohibited. Its 3D analogue, a weak topological insulator (WTI), possesses similar quasi-1D topological states confined at side surfaces. The enhanced confinement could provide a route for dissipationless current and better advantages for applications relative to strong topological insulators (STIs). However, the topological side surface is usually not cleavable and is thus hard to observe. Here, we visualize the topological states of the WTI candidate ZrTe5 by spin and angle-resolved photoemission spectroscopy (ARPES): a quasi-1D band with spin-momentum locking was revealed on the side surface. We further demonstrate that the bulk band gap is controlled by external strain, realizing a more stable WTI state or an ideal Dirac semimetal (DS) state. The highly directional spin-current and the tunable band gap in ZrTe5 will provide an excellent platform for applications.

Observation and control of the weak topological insulator state in ZrTe5 / Zhang, P.; Noguchi, R.; Kuroda, K.; Lin, C.; Kawaguchi, K.; Yaji, K.; Harasawa, A.; Lippmaa, M.; Nie, S.; Weng, H.; Kandyba, V.; Giampietri, A.; Barinov, A.; Li, Q.; Gu, G. D.; Shin, S.; Kondo, T.. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - 12:1(2021), p. 406. [10.1038/s41467-020-20564-8]

Observation and control of the weak topological insulator state in ZrTe5

Giampietri A.;
2021

Abstract

A quantum spin Hall (QSH) insulator hosts topological states at the one-dimensional (1D) edge, along which backscattering by nonmagnetic impurities is strictly prohibited. Its 3D analogue, a weak topological insulator (WTI), possesses similar quasi-1D topological states confined at side surfaces. The enhanced confinement could provide a route for dissipationless current and better advantages for applications relative to strong topological insulators (STIs). However, the topological side surface is usually not cleavable and is thus hard to observe. Here, we visualize the topological states of the WTI candidate ZrTe5 by spin and angle-resolved photoemission spectroscopy (ARPES): a quasi-1D band with spin-momentum locking was revealed on the side surface. We further demonstrate that the bulk band gap is controlled by external strain, realizing a more stable WTI state or an ideal Dirac semimetal (DS) state. The highly directional spin-current and the tunable band gap in ZrTe5 will provide an excellent platform for applications.
2021
Weak Topological Insulator; ZrTe5; Angle-Resolved Photoemission
01 Pubblicazione su rivista::01a Articolo in rivista
Observation and control of the weak topological insulator state in ZrTe5 / Zhang, P.; Noguchi, R.; Kuroda, K.; Lin, C.; Kawaguchi, K.; Yaji, K.; Harasawa, A.; Lippmaa, M.; Nie, S.; Weng, H.; Kandyba, V.; Giampietri, A.; Barinov, A.; Li, Q.; Gu, G. D.; Shin, S.; Kondo, T.. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - 12:1(2021), p. 406. [10.1038/s41467-020-20564-8]
File allegati a questo prodotto
File Dimensione Formato  
Zhang_Observation and control_2021.pdf

accesso aperto

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Creative commons
Dimensione 1.57 MB
Formato Adobe PDF
1.57 MB Adobe PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1550110
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 44
  • ???jsp.display-item.citation.isi??? 42
social impact