In order to explain the anisotropic Rashba-Bychkov effect observed in several metallic surface-state systems, we use k.p perturbation theory with a simple group-theoretical analysis and construct effective Rashba Hamiltonians for different point groups up to third order in the wavenumber. We perform relativistic ab initio calculations for the Bi/Ag(111) ordered surface alloy and from the calculated splitting of the band dispersion we find evidence of the predicted third-order terms. Furthermore, we derive expressions for the corresponding third-order Rashba parameters to provide a simple explanation to the qualitative difference concerning the Rashba-Bychkov splitting of the surface states at Au(111) and Bi/Ag(111).
@article{arxiv.1110.3953,
title = {Higher-order contributions to the Rashba-Bychkov effect with application to Bi/Ag(111) surface alloy},
author = {Sz. Vajna and E. Simon and A. Szilva and K. Palotas and B. Ujfalussy and L. Szunyogh},
journal= {arXiv preprint arXiv:1110.3953},
year = {2015}
}