Abstract
The energy bands of three-, two-, and one-dimensional (1D) structures are generally split at certain wave-vector values into spin components, a spin splitting (SS) that occurs even without an external magnetic field and reflects the effect of spin-orbit interaction on certain symmetries. We show via atomistic theory that 1D quantum wires made of conventional zinc-blende semiconductors have unexpected zero SS for all electron and hole bands if the wire is oriented along (001) (belonging to symmetry), and for some of bands if the wire is oriented along (111) (belonging to symmetry). We find that the predicted absence of a Dresselhaus SS in both (001)-oriented and (111)-oriented 1D wires is immune to perturbations lowering their original and structural symmetries, such as alloying of the matrix around the wire or application of an external electric field. Indeed, such perturbations induce only a Rashba SS. We find that the scaling of the SS with the wave vector is dominated by a linear term plus a minor cubic term.
- Received 15 June 2011
DOI:https://doi.org/10.1103/PhysRevB.84.121303
©2011 American Physical Society