Manipulating quantum channels in weak topological insulator nanoarchitectures

Matsumoto, Akihiko; Arita, Takaichi; Takane, Yositake; Yoshimura, Yukinori; Imura, Ken‐Ichiro

doi:10.1103/physrevb.92.195424

Cited by 5 publications

(5 citation statements)

References 43 publications

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“…On one hand, such coupled 1D modes hybridize and become gapped when N z is even, while a single gapless mode remains when N z is odd. [43][44][45] This is typically the situation that underlies a stripe pattern in the Z 2 -index map. On the other hand, stacked QSH layers lead to a WTI in the 3D limit, in which coupled 1D helical modes evolve into two helical Dirac cones that appear on side surfaces of a WTI.…”

Section: Mapping the Topological Indexmentioning

confidence: 99%

Comparative study of Weyl semimetal and topological/Chern insulators: Thin-film point of view

et al. 2016

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Regarding three-dimensional (3D) topological insulators and semimetals as a stack of constituent 2D topological (or sometimes non-topological) systems is a useful viewpoint. Here, we perform a comparative study of the paradigmatic 3D topological phases: Weyl semimetal (WSM), strong vs. weak topological insulators (STI/WTI), and Chern insulator (CI). By calculating the Z-and Z2-indices for the thin films of such 3D topological phases, we follow dimensional evolution of topological properties from 2D to 3D. It is shown that the counterpart of STI and WTI in the time-reversal symmetry broken CI system are, respectively, WSM and CI phases. The number ND of helical Dirac cones emergent on the surface of a topological insulator is shown to be identical to the number NW of the pairs of Weyl cones in the corresponding WSM phase: ND = NW . To test the robustness of this scenario against disorder, we have studied the transport property of disordered WSM thin films, taking into account both the bulk and surface contributions.

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Section: Mapping the Topological Indexmentioning

confidence: 99%

Comparative study of Weyl semimetal and topological/Chern insulators: Thin-film point of view

et al. 2016

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“…This method can be straightforwardly generalized to systems of higher dimensionality [55]. Such 2D systems with trivial Chern number but non-trivial Zak's phase along certain 1D edges have also been referred to as weak 2D topological insulators [56][57][58] In the context of the 2D SSH model considered here, the presence of topological edge states has been recently linked to a non-trivial 2D Zak's phase [50] (generalization of Zak's phase to 2D lattices). The results we find below are consistent with this finding.…”

Section: State In Xoymentioning

confidence: 99%

Topological bound states in interacting Su–Schrieffer–Heeger rings

Marques

Dias

2018

J. Phys.: Condens. Matter

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We study two-particle states in a Su-Schrieffer-Heeger (SSH) chain with periodic boundary conditions and nearest-neighbor (NN) interactions. The system is mapped into a problem of a single particle in a two-dimensional (2D) SSH lattice with potential walls along specific edges. The 2D SSH model has a trivial Chern number but a non-trivial Zak's phase, the one-dimensional (1D) topological invariant, along specific directions of the lattice, which allow for the presence of topological edge states. Using center-of-mass and relative coordinates, we calculate the energy spectrum of these two-body states for strong interactions and find that, aside from the expected appearance of doublon bands, two extra in-gap bands are present. These are identified as bands of topological states localized at the edges of the internal coordinate, the relative distance between the two particles. As such, the topological states reported here are intrinsically many-body in what concerns their real space manifestation, having no counterpart in single-particle states derived from effective models. Finally, we compare the effect of Hubbard interactions with that of NN interactions to show how the presence of the topological bound states is specific to the latter case.

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“…• Surface states in topological insulators. In topological insulators, surface states can lead to perfectly conducting channels which are protected against scattering due to disorder [18].…”

Section: Introductionmentioning

confidence: 99%

Quantum dragon solutions for electron transport through nanostructures based on rectangular graphs

Inkoom

Novotny

2018

J. Phys. Commun.

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Electron transport through nanodevices of atoms in a single-layer rectangular arrangement with free (open) boundary conditions parallel to the direction of the current flow is studied within the singleband tight binding model. The Landauer formula gives the electrical conductance to be a function of the electron transmission probability, ( ) E , as a function of the energy E of the incoming electron. A quantum dragon nanodevice is one which has a perfectly conducting channel, namely  = ( ) E 1 for all energies which are transmitted by the external leads even though there may be arbitrarily strong electron scattering. The rectangular single-layer systems are shown to be able to be quantum dragon devices, both for uniform leads and for dimerized leads. The quantum dragon condition requires appropriate lead-device connections and correlated randomness in the device. F .

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Manipulating quantum channels in weak topological insulator nanoarchitectures

Cited by 5 publications

References 43 publications

Comparative study of Weyl semimetal and topological/Chern insulators: Thin-film point of view

Comparative study of Weyl semimetal and topological/Chern insulators: Thin-film point of view

Topological bound states in interacting Su–Schrieffer–Heeger rings

Quantum dragon solutions for electron transport through nanostructures based on rectangular graphs

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