8 research outputs found
Non-Dirac topological surface states in (SnTe)(BiTe)
A new type of topological spin-helical surface states was discovered in
layered van der Waals bonded (SnTe)(BiTe) compounds
which comprise two covalently bonded band inverted subsystems, SnTe and
BiTe, within a building block. This novel topological states
demonstrate non-Dirac dispersion within the band gap. The dispersion of the
surface state has two linear sections of different slope with shoulder feature
between them. Such a dispersion of the topological surface state enables
effective switch of the velocity of topological carriers by means of applying
an external electric field
New interpretation of the origin of 2DEG states at the surface of layered topological insulators
On the basis of relativistic ab-initio calculations we show that the driving
mechanism of simultaneous emergence of parabolic and M-shaped 2D electron gas
(2DEG) bands at the surface of layered topological insulators as well as
Rashba-splitting of the former states is an expansion of van der Waals (vdW)
spacings caused by intercalation of metal atoms or residual gases. The
expansion of vdW spacings and emergence of the 2DEG states localized in the
(sub)surface region are also accompanied by a relocation of the topological
surface state to the lower quintuple layers, that can explain the absence of
interband scattering found experimentally.Comment: 5 pages, 4 figure
Magnetic extension as an efficient method for realizing the quantum anomalous hall state in topological insulators
Ab initio study of the adsorption, diffusion, and intercalation of alkali metal atoms on the (0001) surface of the topological insulator Bi2Se3
Ab initio study of the adsorption, diffusion, and intercalation of alkali metal adatoms on the (0001) step surface of the topological insulator Bi2Se3 has been performed for the case of low coverage. The calculations of the activation energies of diffusion of adatoms on the surface and in van der Waals gaps near steps, as well as the estimate of diffusion lengths, have shown that efficient intercalation through steps is possible only for Li and Na. Data obtained for K, Rb, and Cs atoms indicate that their thermal desorption at high temperatures can occur before intercalation. The results have been discussed in the context of existing experimental data.Peer Reviewe