Unconventional spin texture of a topologically nontrivial semimetal Sb(110)

TL;DR

This study combines theoretical and experimental methods to reveal an unconventional spin texture on Sb(110) surfaces, showing unique spin polarization and scattering properties relevant for topological semimetals.

Contribution

It provides the first detailed analysis of the spin texture of Sb(110) surface states using spin-resolved DFT and STM, highlighting their unconventional nature.

Findings

Unconventional spin texture confirmed by spin-resolved calculations.

Absence of direct backscattering signals observed in STM.

Identification of allowed scattering vectors and their evolution.

Abstract

The surfaces of antimony are characterized by the presence of spin-split states within the projected bulk band gap and the Fermi contour is thus expected to exhibit a spin texture. Using spin-resolved density functional theory calculations, we determine the spin polarization of the surface bands of Sb(110). The existence of the unconventional spin texture is corroborated by the investigations of the electron scattering on this surface. The charge interference patterns formed around single scattering impurities, imaged by scanning tunneling microscopy, reveal the absence of direct backscattering signal. We identify the allowed scattering vectors and analyze their bias evolution in relation to the surface-state dispersion.