Nonlocal edge state transport in topological insulators

@article{Protogenov2013NonlocalES,
  title={Nonlocal edge state transport in topological insulators},
  author={Alexander P. Protogenov and Evgueni V. Chulkov and Valery A. Verbus},
  journal={Physical Review B},
  year={2013},
  volume={88},
  pages={195431}
}
We use the $N$-terminal scheme for studying the edge-state transport in two-dimensional topological insulators. We find the universal nonlocal response in the ballistic transport approach. This macroscopic exhibition of the topological order offers different areas for applications. 

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References

SHOWING 1-10 OF 21 REFERENCES

The birth of topological insulators

Certain insulators have exotic metallic states on their surfaces that render the electrons travelling on such surfaces insensitive to scattering by impurities, possibly finding uses in technological applications in spintronics and quantum computing.

Two-dimensional surface charge transport in topological insulators

The dominant scattering angles can be inferred by studying the ratio of the transport time to the Bloch lifetime as a function of the Wigner-Seitz radius rs. The current generates a spin polarization

Spin‐helical transport in normal and superconducting topological insulators

In a topological insulator (TI) the character of electron transport varies from insulating in the interior of the material to metallic near its surface. Unlike, however, ordinary metals, conducting

Anomalous edge transport in the quantum anomalous Hall state.

Here, the edge transport with both chiral and nonchiral states is studied by the Landauer-Büttiker formalism and it is found that the longitudinal resistance is nonzero, whereas Hall resistance is quantized to h/e2.

Evidence for the ballistic intrinsic spin Hall effect in HgTe nanostructures

Non-local transport measurements on mercury telluride quantum wells show clear signatures of the ballistic spin Hall effect. The ballistic nature of the experiment allows the observed effect to be

Surface Hall Effect and Nonlocal Transport in SmB6: Evidence for Surface Conduction

These results serve as proof that at low temperatures SmB6 has a metallic surface that surrounds an insulating bulk, paving the way for transport studies of the surface state in this proposed TKI material.

Nonlocal Transport in the Quantum Spin Hall State

The data confirm that the quantum transport through the (helical) edge channels is dissipationless and that the contacts lead to equilibration between the counterpropagating spin states at the edge, which agree quantitatively with the theory of the quantum spin Hall effect.

Finite size effects on helical edge states in a quantum spin-Hall system.

Through analytical solutions in a model calculation for a strip of finite width, it is found that edge states on the two sides can couple together to produce a gap in the spectrum, destroying the quantum spin-Hall effect.

Quantum spin Hall effect in graphene.

Graphene is converted from an ideal two-dimensional semimetallic state to a quantum spin Hall insulator and the spin and charge conductances in these edge states are calculated and the effects of temperature, chemical potential, Rashba coupling, disorder, and symmetry breaking fields are discussed.

Spin polarization of the quantum spin Hall edge states

The quantum spin Hall state is predicted to consist of two oppositely polarized spin currents travelling in opposite directions around the edges of a topological insulator. Non-local measurements of