Spatial aspects of spin polarization of structurally split surface states in thin films with magnetic exchange and spin–orbit interaction

A theoretical study is presented of the effect of an in-plane magnetic exchange field on the band structure of centrosymmetric films of noble metals and topological insulators. Based on an ab initio relativistic \mathbf{k}\cdot\mathbf{p}theory, a minimal effective model is developed that describes two coupled copies of a Rashba or Dirac electronic system residing at the opposite surfaces of the film. The coupling leads to a structural gap at...