@article {10856,
	title = {In-plane noncollinear exchange coupling mediated by helical edge states in quantum spin Hall systems},
	journal = {Physical Review B - Condensed Matter and Materials Physics},
	year = {2009},
	doi = {10.1103/PhysRevB.80.241302},
	author = {Jinhua Gao and Weiqiang Chen and X.C. Xie and Fu-Chun Zhang}
}
