Pure spin current and perfect valley filter by designed separation of the chiral states in two-dimensional honeycomb lattices
arXiv:1610.02546 · doi:10.1103/PhysRevB.94.155112
Abstract
We propose a realization of pure spin currents and perfect valley filter based on a quantum anomalous Hall insulator, around which edge states with up-spin and down-spin circulate. By applying staggered sublattice potential on the strips along the edges of sample, the edge states with down spin can be pushed into the inner boundaries of the strips while the other edge states with up spin remain on the outer boundaries, resulting in spatially separated chiral states with perfect spin polarization. Moreover, a valley filter, which is immune to short-range and smooth long-range scatterers, can be engineered by additionally applying boundary potentials on the outmost lattices of the sample. We also find that the boundary potential can be used to control the size effect induced oscillation of the inner chiral states. The connection of the boundary potential to size effect is revealed.
References in corpus (12)
- Substrate-induced band gap opening in epitaxial graphene
- Valley filter and valley valve in graphene
- Electronic States of Graphene Nanoribbons
- Photo-Induced Topological Phase Transition and a Single Dirac-Cone State in Silicene
- Topological confinement in bilayer graphene
- Finite size effects of helical edge states in HgTe/CdTe quantum wells
- Edge states in Graphene: from gapped flat band to gapless chiral modes
- Structural and electronic properties of germanene on MoS
- Valley-polarized quantum anomalous Hall phase and disorder induced valley-filtered chiral edge channels
- Magnetization signatures of light-induced quantum Hall edge states
- Spin-Hall effect in triplet chiral superconductors and graphene
- Finite Size Effect in the Quantum Anomalous Hall system