Itinerant Ferromagnetism in Rashba Spin-Orbit Coupled Semiconductors

We theoretically studied the itinerant ferromagnetism in the Rashba spin-orbit coupled 2D electron system by oppositely shifting the two spin-split Fermi surfaces, on condition that electric current vanishes. We found that the system is stable for the infinitesimal displacements only if rs is smaller than around 10. But when rs becomes much larger than 10, the system becomes unstable at the original state, and finally we obtained another stable state with nonzero spin polarisation.