| Full text | |
| Author(s): |
Matusalem, Filipe
;
Marques, Marcelo
;
Teles, Lara K.
;
Matthes, Lars
;
Furthmueller, Juergen
;
Bechstedt, Friedhelm
Total Authors: 6
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW B; v. 100, n. 24, p. 10-pg., 2019-12-24. |
| Abstract | |
The third-rank tensor of the static spin Hall conductivity is investigated for two-dimensional (2D) topological insulators by electronic structure calculations. For highly symmetric hexagonal systems its numerical values are close to the conductance quantum e(2)/h, independent of the gap size. 2D crystals with a square Bravais lattice present similar effects, while rectangular translational symmetry yields conductivity values much below e(2)/h, showing that a quantum spin Hall phase is not generally characterized by a quantized spin Hall conductivity. Vertical electric fields applied to hexagonal 2D crystals strongly reduce the conductivity, despite the conservation of the quantum spin Hall state up to a critical field strength. Weak symmetry-conserving biaxial but also symmetry-lowering uniaxial strain has a minor influence as long as inverted gaps dictate the topological character. The results are discussed in terms of the atomic geometry and the Rashba contribution to the spin-orbit interaction (SOI) using a tight-binding approximation. Translational and point-group symmetry as well as SOI rule the deviation from the quantization of the spin Hall conductance. (AU) | |
| FAPESP's process: | 14/13907-7 - Physical properties of two-dimensional materials |
| Grantee: | Lara Kühl Teles |
| Support Opportunities: | Research Grants - Visiting Researcher Grant - International |