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Engineering Dirac electrons emergent on the surface of a topological insulator

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ABSTRACT

The concept of the topological insulator (TI) has introduced a new point of view to condensed-matter physics, relating a priori unrelated subfields such as quantum (spin, anomalous) Hall effects, spin–orbit coupled materials, some classes of nodal superconductors, superfluid 3He, etc. From a technological point of view, TIs are expected to serve as platforms for realizing dissipationless transport in a non-superconducting context. The TI exhibits a gapless surface state with a characteristic conic dispersion (a surface Dirac cone). Here, we review peculiar finite-size effects applicable to such surface states in TI nanostructures. We highlight the specific electronic properties of TI nanowires and nanoparticles, and in this context we contrast the cases of weak and strong TIs. We study the robustness of the surface and the bulk of TIs against disorder, addressing the physics of Dirac and Weyl semimetals as a new research perspective in the field.

No MeSH data available.


Spatial profile of low-lying electronic wave function along a step of height (a) one, and (b) two. In (a) a perfectly conducting channel is realized. See also [18].
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Figure 4: Spatial profile of low-lying electronic wave function along a step of height (a) one, and (b) two. In (a) a perfectly conducting channel is realized. See also [18].

Mentions: The even/odd feature on the spectrum of a WTI sample with side surfaces is equally applied to a system with atomic scale steps on the gapped surfaces [18]. In figure 4, we show the spatial profile of the wave function of some low-lying states in a geometry with an atomic scale step. In figure 4(a), the height of the step Nh is 1, while in figure 4(b), the step is 2 atomic scale high. As shown in the two panels, the wave function has strong amplitude along the step when Nh is odd, while it has visibly no weight in the step region when Nh is even.


Engineering Dirac electrons emergent on the surface of a topological insulator
Spatial profile of low-lying electronic wave function along a step of height (a) one, and (b) two. In (a) a perfectly conducting channel is realized. See also [18].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036486&req=5

Figure 4: Spatial profile of low-lying electronic wave function along a step of height (a) one, and (b) two. In (a) a perfectly conducting channel is realized. See also [18].
Mentions: The even/odd feature on the spectrum of a WTI sample with side surfaces is equally applied to a system with atomic scale steps on the gapped surfaces [18]. In figure 4, we show the spatial profile of the wave function of some low-lying states in a geometry with an atomic scale step. In figure 4(a), the height of the step Nh is 1, while in figure 4(b), the step is 2 atomic scale high. As shown in the two panels, the wave function has strong amplitude along the step when Nh is odd, while it has visibly no weight in the step region when Nh is even.

View Article: PubMed Central - PubMed

ABSTRACT

The concept of the topological insulator (TI) has introduced a new point of view to condensed-matter physics, relating a priori unrelated subfields such as quantum (spin, anomalous) Hall effects, spin–orbit coupled materials, some classes of nodal superconductors, superfluid 3He, etc. From a technological point of view, TIs are expected to serve as platforms for realizing dissipationless transport in a non-superconducting context. The TI exhibits a gapless surface state with a characteristic conic dispersion (a surface Dirac cone). Here, we review peculiar finite-size effects applicable to such surface states in TI nanostructures. We highlight the specific electronic properties of TI nanowires and nanoparticles, and in this context we contrast the cases of weak and strong TIs. We study the robustness of the surface and the bulk of TIs against disorder, addressing the physics of Dirac and Weyl semimetals as a new research perspective in the field.

No MeSH data available.