Topological surface states protected from backscattering by chiral spin texture
Pedram Roushan, Jungpil Seo, Colin V. Parker, Y. S. Hor, D. Hsieh, Dong Qian, Anthony Richardella, M. Z. Hasan, R. J. Cava, Ali Yazdani
Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated because of the strong sping-orbit coupling inherent to these systems. These materials are distinguished from ordinary insulators by the presence of gapless metallic surface states, resembling chiral edge modes in quantum Hall systems, but with unconventional spin textures. A key predicted feature of such spin-textured boundary states is their insensitivity to spin-independent scattering, which is thought to protect them from backscattering and localization. Recently, experimental and theoretical efforts have provided strong evidence for the existence of both two- and three-dimensional classes of such topological insulator materials in semiconductor quantum well structures and several bismuth-based compounds, but so far experiments have not probed the sensitivity of these chiral states to scattering. Here we use scanning tunnelling spectroscopy and angle-resolved photoemission spectroscopy to visualize the gapless surface states in the three-dimensional topological insulator Bi1-xSbx, and examine in detail the influence of scattering from disorder caused by random alloying in this compound. We show that, despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observations demonstrate that the chiral nature of these states protects the spin of the carriers. These chiral states are therefore potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing.
https://doi.org/10.1038/nature08308
10.1038/nature08308
Dive into the research topics of 'Topological surface states protected from backscattering by chiral spin texture'. Together they form a unique fingerprint.
Photoelectron Spectroscopy Medicine & Life Sciences 100%
Semiconductors Medicine & Life Sciences 95%
Bismuth Medicine & Life Sciences 93%
Orbit Medicine & Life Sciences 73%
Electronic Data Processing Medicine & Life Sciences 68%
Spectrum Analysis Medicine & Life Sciences 66%
Roushan, P., Seo, J., Parker, C. V., Hor, Y. S., Hsieh, D., Qian, D., Richardella, A., Hasan, M. Z., Cava, R. J., & Yazdani, A. (2009). Topological surface states protected from backscattering by chiral spin texture. Nature, 460(7259), 1106-1109. https://doi.org/10.1038/nature08308
Roushan, Pedram ; Seo, Jungpil ; Parker, Colin V. ; Hor, Y. S. ; Hsieh, D. ; Qian, Dong ; Richardella, Anthony ; Hasan, M. Z. ; Cava, R. J. ; Yazdani, Ali. / Topological surface states protected from backscattering by chiral spin texture. In: Nature. 2009 ; Vol. 460, No. 7259. pp. 1106-1109.
@article{5f1999ded34c430b8bb0aff33591d35c,
title = "Topological surface states protected from backscattering by chiral spin texture",
abstract = "Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated because of the strong sping-orbit coupling inherent to these systems. These materials are distinguished from ordinary insulators by the presence of gapless metallic surface states, resembling chiral edge modes in quantum Hall systems, but with unconventional spin textures. A key predicted feature of such spin-textured boundary states is their insensitivity to spin-independent scattering, which is thought to protect them from backscattering and localization. Recently, experimental and theoretical efforts have provided strong evidence for the existence of both two- and three-dimensional classes of such topological insulator materials in semiconductor quantum well structures and several bismuth-based compounds, but so far experiments have not probed the sensitivity of these chiral states to scattering. Here we use scanning tunnelling spectroscopy and angle-resolved photoemission spectroscopy to visualize the gapless surface states in the three-dimensional topological insulator Bi1-xSbx, and examine in detail the influence of scattering from disorder caused by random alloying in this compound. We show that, despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observations demonstrate that the chiral nature of these states protects the spin of the carriers. These chiral states are therefore potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing.",
author = "Pedram Roushan and Jungpil Seo and Parker, {Colin V.} and Hor, {Y. S.} and D. Hsieh and Dong Qian and Anthony Richardella and Hasan, {M. Z.} and Cava, {R. J.} and Ali Yazdani",
note = "Funding Information: Acknowledgements We acknowledge K. K. Gomes and A. N. Pasupathy for suggestions about experimental procedure and initial analysis. This work was supported by grants from ONR, ARO, DOE, NSF-DMR and the NSF-MRSEC programme through the Princeton Center for Complex Materials. P.R. acknowledges an NSF graduate fellowship.",
doi = "10.1038/nature08308",
journal = "Nature",
Roushan, P, Seo, J, Parker, CV, Hor, YS, Hsieh, D, Qian, D, Richardella, A, Hasan, MZ, Cava, RJ & Yazdani, A 2009, 'Topological surface states protected from backscattering by chiral spin texture', Nature, vol. 460, no. 7259, pp. 1106-1109. https://doi.org/10.1038/nature08308
Topological surface states protected from backscattering by chiral spin texture. / Roushan, Pedram; Seo, Jungpil; Parker, Colin V.; Hor, Y. S.; Hsieh, D.; Qian, Dong; Richardella, Anthony; Hasan, M. Z.; Cava, R. J.; Yazdani, Ali.
In: Nature, Vol. 460, No. 7259, 27.08.2009, p. 1106-1109.
T1 - Topological surface states protected from backscattering by chiral spin texture
AU - Roushan, Pedram
AU - Seo, Jungpil
AU - Parker, Colin V.
AU - Hor, Y. S.
AU - Hsieh, D.
AU - Qian, Dong
AU - Richardella, Anthony
AU - Hasan, M. Z.
AU - Cava, R. J.
AU - Yazdani, Ali
N1 - Funding Information: Acknowledgements We acknowledge K. K. Gomes and A. N. Pasupathy for suggestions about experimental procedure and initial analysis. This work was supported by grants from ONR, ARO, DOE, NSF-DMR and the NSF-MRSEC programme through the Princeton Center for Complex Materials. P.R. acknowledges an NSF graduate fellowship.
N2 - Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated because of the strong sping-orbit coupling inherent to these systems. These materials are distinguished from ordinary insulators by the presence of gapless metallic surface states, resembling chiral edge modes in quantum Hall systems, but with unconventional spin textures. A key predicted feature of such spin-textured boundary states is their insensitivity to spin-independent scattering, which is thought to protect them from backscattering and localization. Recently, experimental and theoretical efforts have provided strong evidence for the existence of both two- and three-dimensional classes of such topological insulator materials in semiconductor quantum well structures and several bismuth-based compounds, but so far experiments have not probed the sensitivity of these chiral states to scattering. Here we use scanning tunnelling spectroscopy and angle-resolved photoemission spectroscopy to visualize the gapless surface states in the three-dimensional topological insulator Bi1-xSbx, and examine in detail the influence of scattering from disorder caused by random alloying in this compound. We show that, despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observations demonstrate that the chiral nature of these states protects the spin of the carriers. These chiral states are therefore potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing.
AB - Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated because of the strong sping-orbit coupling inherent to these systems. These materials are distinguished from ordinary insulators by the presence of gapless metallic surface states, resembling chiral edge modes in quantum Hall systems, but with unconventional spin textures. A key predicted feature of such spin-textured boundary states is their insensitivity to spin-independent scattering, which is thought to protect them from backscattering and localization. Recently, experimental and theoretical efforts have provided strong evidence for the existence of both two- and three-dimensional classes of such topological insulator materials in semiconductor quantum well structures and several bismuth-based compounds, but so far experiments have not probed the sensitivity of these chiral states to scattering. Here we use scanning tunnelling spectroscopy and angle-resolved photoemission spectroscopy to visualize the gapless surface states in the three-dimensional topological insulator Bi1-xSbx, and examine in detail the influence of scattering from disorder caused by random alloying in this compound. We show that, despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observations demonstrate that the chiral nature of these states protects the spin of the carriers. These chiral states are therefore potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing.
U2 - 10.1038/nature08308
DO - 10.1038/nature08308
JO - Nature
JF - Nature
Roushan P, Seo J, Parker CV, Hor YS, Hsieh D, Qian D et al. Topological surface states protected from backscattering by chiral spin texture. Nature. 2009 Aug 27;460(7259):1106-1109. https://doi.org/10.1038/nature08308