Dzyaloshinskii-Moriya interaction mediated by spin-polarized band with Rashba spin-orbit coupling

Dzyaloshinskii-Moriya interaction (DMI) plays a central role in breaking chiral symmetry of magnetic domain wall structure. The recently observed chiral dependence of domain wall structures in ultrathin magnetic films with perpendicular anisotropy indicates the presence of a strong DMI. We calculate the indirect exchange interaction between magnetic ions mediated by spin-polarized conduction electrons with a Rashba spin-orbit coupling. We find the resulting DMI increases with the spin-orbit coupling strength, but decreases with the spin-polarization of the conduction electrons. The estimated DMI magnitude is comparable to the experimental results.