Abstract
For three-dimensional topological insulators in the family, topological surface states with orbitals have a left-handed spin texture for the upper Dirac cone and a right-handed spin texture for the lower Dirac cone. In this work, we predict a new form of the spin-orbital texture associated with the and orbitals. For the upper Dirac cone, a left-handed (right-handed) spin texture is coupled to the “radial” (“tangential”) orbital texture, whereas for the lower Dirac cone, the coupling of spin and orbital textures is the exact opposite. The “tangential” (“radial”) orbital texture is dominant for the upper (lower) Dirac cone, leading to the right-handed spin texture for the in-plane orbitals of both the upper and lower Dirac cones. A spin-resolved and photon polarized angle-resolved photoemission spectroscopy experiment is proposed to observe this novel spin-orbital texture.
- Received 22 November 2012
DOI:https://doi.org/10.1103/PhysRevLett.111.066801
© 2013 American Physical Society