Surface states scattering from a step defect in the topological insulator Bi2Te3
In: Physical Review B, Jg. 86 (2012-10-12)
Online
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Zugriff:
We study theoretically, using a quantum-mechanical approach, the general scattering problem of a straight step defect on the surface of the topological insulator ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ with a strong warping effect. At high energy where the warping effect is large, an electron incident on a step defect running along $\ensuremath{\Gamma}\ensuremath{-}M$ may exhibit perfect transmission whereas an electron incident on a defect running along $\ensuremath{\Gamma}\ensuremath{-}K$ has a finite probability of being reflected and may even exhibit resonant total reflection. The transmission in the latter case is also sensitive to whether there is particle-hole symmetry in the system. Although backscattering is prohibited by time-reversal symmetry, an electron incident nearly normally on a defect running along $\ensuremath{\Gamma}\ensuremath{-}K$ has a finite reflection. This is interpreted as the consequence of the existence of decaying modes localized at the defect, acting as a magnetic barrier for the propagating modes. The predicted Friedel oscillations and the power-law decay behavior of the local density of states (LDOS) near the defect are in good agreement with recent scanning tunneling microscopy experiments on ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$. The high-energy LDOS of the surface states is also found to show multiperiodic Friedel oscillations, caused by the competing characteristic scattering processes.
Titel: |
Surface states scattering from a step defect in the topological insulator Bi2Te3
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Autor/in / Beteiligte Person: | An, Jin ; Ting, C. S. |
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Zeitschrift: | Physical Review B, Jg. 86 (2012-10-12) |
Veröffentlichung: | American Physical Society (APS), 2012 |
Medientyp: | unknown |
ISSN: | 1550-235X (print) ; 1098-0121 (print) |
DOI: | 10.1103/physrevb.86.165313 |
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