Topological surface states are a class of novel electronic states that are of potential interest in quantum computing or spintronic applications1,2,3,4,5,6,7. Unlike conventional two-dimensional electron states, these surface states are expected to be immune to localization and to overcome barriers caused by material imperfection8,9,10,11,12,13,14. Previous experiments have demonstrated that topological surface states do not backscatter between equal and opposite momentum states, owing to their chiral spin texture15,16,17,18. However, so far there is no evidence that these states in fact transmit through naturally occurring surface defects. Here we use a scanning tunnelling microscope to measure the transmission and reflection probabilities of topological surface states of antimony through naturally occurring crystalline steps separating atomic terraces. In contrast to non-topological surface states of common metals (copper, silver and gold)19,20,21,22,23, which are either reflected or absorbed by atomic steps, we show that topological surface states of antimony penetrate such barriers with high probability. This demonstration of the extended nature of antimony’s topological surface states suggests that such states may be useful for high current transmission even in the presence of atomic-scale irregularities—an electronic feature sought to efficiently interconnect nanoscale devices.
This is a preview of subscription content
Subscription info for Chinese customers
We have a dedicated website for our Chinese customers. Please go to naturechina.com to subscribe to this journal.
Get time limited or full article access on ReadCube.
All prices are NET prices.
Kane, C. L. & Mele, E. J. Z2 topological order and the quantum spin Hall effect. Phys. Rev. Lett. 95, 146802 (2005)
Moore, J. E. & Balents, L. Topological invariants of time-reversal-invariant band structures. Phys. Rev. B 75, 121306(R) (2007)
Fu, L., Kane, C. L. & Mele, E. J. Topological insulators in three dimensions. Phys. Rev. Lett. 98, 106803 (2007)
Roy, R. Z2 classification of quantum spin Hall systems: an approach using time-reversal invariance. Phys. Rev. B 79, 195321 (2009)
Bernevig, B. A., Hughes, T. L. & Zhang, S.-C. Quantum spin Hall effect and topological phase transition in HgTe quantum wells. Science 314, 1757–1761 (2006)
König, M. et al. Quantum spin Hall insulator state in HgTe quantum wells. Science 318, 766–770 (2007)
Zhang, H. et al. Topological insulators in Bi2Te3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface. Nature Phys. 5, 438–442 (2009)
Hsieh, D. et al. Observation of unconventional quantum spin textures in topological insulators. Science 323, 919–922 (2009)
Hsieh, D. et al. A topological Dirac insulator in a quantum spin Hall phase. Nature 452, 970–974 (2008)
Chen, Y. L. et al. Experimental realization of a three-dimensional topological insulator, Bi2Te3 . Science 325, 178–181 (2009)
Li, Y.-Y. et al. Growth dynamics and thickness-dependent electronic structure of topological insulator Bi2Te3 thin films on Si. Preprint at 〈http://arxiv.org/abs/0912.5054v1〉 (2009)
Guo, H.-M. & Franz, M. Theory of quasiparticle interference on the surface of a strong topological insulator. Phys. Rev. B 81, 041102(R) (2010)
Biswas, R. R. & Balatsky, A. V. Scattering from surface step edges in strong topological insulators. Preprint at 〈http://arxiv.org/abs/0912.4477v2〉 (2010)
Zhou, X., Fang, C., Tasi, W.-F. & Hu, J. Theory of quasiparticle scattering in a two-dimensional system of helical Dirac fermions: surface band structure of a three-dimensional topological insulator. Phys. Rev. B 80, 245317 (2009)
Roushan, P. et al. Topological surface states protected from backscattering by chiral spin texture. Nature 460, 1106–1109 (2009)
Alpichshev, Z. et al. STM imaging of electronic waves on the surface of Bi2Te3: topologically protected surface states and hexagonal warping effects. Phys. Rev. Lett. 104, 016401 (2010)
Zhang, T. et al. Experimental demonstration of the topological surface states protected by the time-reversal symmetry. Phys. Rev. Lett. 103, 266803 (2009)
Gomes, K. K. et al. Quantum imaging of topologically unpaired spin-polarized Dirac fermions. Preprint at 〈http://arxiv.org/abs/0909.0921v2〉 (2009)
Bürgi, L., Jeandupeux, O., Brune, H. & Kern, K. Probing hot-electron dynamics at surfaces with a cold scanning tunneling microscope. Phys. Rev. Lett. 82, 4516–4519 (1999)
Bürgi, L., Jeandupeux, O., Hirstein, A., Brune, H. & Kern, K. Confinement of surface state electrons in Fabry-Pérot resonators. Phys. Rev. Lett. 81, 5370–5373 (1998)
Crommie, M. F., Lutz, C. P. & Eigler, D. M. Imaging standing waves in a two-dimensional electron gas. Nature 363, 524–527 (1993)
Avouris, P. & Lyo, I.-W. Observation of quantum size effects at room temperature on metal surfaces with STM. Science 264, 942–945 (1993)
Mugarza, A. et al. Lateral quantum wells at vicinal Au(111) studied with angle-resolved photoemission. Phys. Rev. B 66, 245419 (2002)
Pivetta, M., Silly, F., Patthey, F., Pelz, J. P. & Schneider, W.-D. Reading the ripples of confined surface-state electrons: profiles of constant integrated local density of states. Phys. Rev. B 67, 193402 (2003)
Li, J., Schneider, W.-D., Berndt, R. & Crampin, S. Electron confinement to nanoscale Ag islands on Ag(111): a quantitative study. Phys. Rev. Lett. 80, 3332–3335 (1998)
Heller, E. J., Crommie, M. F., Lutz, C. P. & Eigler, D. M. Scattering and absorption of surface electron waves in quantum corrals. Nature 369, 464–466 (1994)
Fiete, G. A. & Heller, E. J. Theory of quantum corrals and quantum mirages. Rev. Mod. Phys. 75, 933–948 (2003)
We gratefully acknowledge discussions with B. A. Bernevig, B. Boyanov, M. Z. Hasan and N. P. Ong. This work was supported by grants from the NSF-MRSEC programme through the Princeton Center for Complex Materials, the ARO, the DOE, the NSF-DMR and the W. M. Keck Foundation. P.R. acknowledges support by a NSF graduate fellowship.
The authors declare no competing financial interests.
About this article
Cite this article
Seo, J., Roushan, P., Beidenkopf, H. et al. Transmission of topological surface states through surface barriers. Nature 466, 343–346 (2010). https://doi.org/10.1038/nature09189
Nature Communications (2022)
Observation of a giant mass enhancement in the ultrafast electron dynamics of a topological semimetal
Communications Physics (2021)
npj Quantum Materials (2020)
Nano Research (2020)
Enhanced linear magneto-resistance near the Dirac point in topological insulator Bi2(Te1−xSex)3 nanowires
Nano Research (2020)