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

TL;DR

This paper demonstrates that moderate spin-orbit coupling in 2D magnetic semiconductors creates localized edge states at domain walls, with their properties determined by topological invariants, and suggests experimental detection methods.

Contribution

It reveals how spin-orbit coupling induces topologically protected localized states at magnetic domain walls in 2D semiconductors, linking spin accumulation to real-space topological numbers.

Findings

Localized edge states depend on spin-orbit coupling strength

Spin accumulation occurs perpendicular to ferromagnetic order at domain walls

Potential for experimental observation via spin density or conduction measurements

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.