Indirect exchange interaction via electrons in spin–orbit coupled bands in semiconductors

Abstract

Abstract Indirect coupling between two localized magnetic moments in a semiconductor is considered. This coupling may be of two origins: due to intraband electron transitions (RKKY) and virtual interband transitions, the latter being of particular importance in materials considered. Strong spinorbit coupling between electronic bands leads to a complicated form of the effective Hamiltonian. It no longer contains a Heisenberg term only. The number of independent constants describing the interaction depends on the symmetry of the interacting pair. The special case of zincblende structure is considered. Several simple models are reviewed and found insufficient to describe the indirect interaction, at least for closely lying moments, a fact which stresses the necessity of numerical calculations.