Theoretical model for Rashba spin-orbit interaction in d electrons
Abstract
We show that the Rashba spin-orbit interaction in d electron solids, which originates from the broken inversion symmetry at surfaces or interfaces, is strongly dependent on the orbital characters of the bands involved. This is studied by developing a tight-binding model in the presence of a uniform perpendicular electric field and spin-orbit coupling. We argue that for valence electrons, the spin-orbit coupling strength scales only as the square of the atomic number. The electric field distorts the d orbitals through the admixture of p and f states and also introduces intersite overlap parameters. Expressions for Rashba coefficients for the bands are obtained in both weak and strong spin-orbit interaction limits and are shown to be orbital dependent. The results are compared with first-principles calculations for model systems, showing good agreement. Our study demonstrates the orbital-dependent gate control of the Rashba effect for the purposes of oxide electronics.
- Publication:
-
Physical Review B
- Pub Date:
- October 2014
- DOI:
- 10.1103/PhysRevB.90.165108
- Bibcode:
- 2014PhRvB..90p5108S
- Keywords:
-
- 73.20.-r;
- 71.10.-w;
- 31.15.A-;
- Electron states at surfaces and interfaces;
- Theories and models of many-electron systems;
- Ab initio calculations