Edge states generated by spin-orbit coupling at domain walls in magnetic semiconductors

Abstract

Electronic states localized at domain walls between ferromagnetically ordered phases in two-dimensional electron systems are generated by moderate spin-orbit coupling. The spin carried by these states depends on the slope of the magnetic background at the domain wall. The number of localized states is determined by a real space topological number, and spin perpendicular to the ferromagnetic order accumulates in these localized states at domain walls. These trapped states may be observed in experiments that probe either spin density or conduction paths in quantum wells.